eChapters

Agriculture in India is one of the most important sectors of its economy. It provides livelihood to almost two thirds of the work force in the country and accounts for 18% of India’s GDP. About 43 % of India’s geographical area is used for agricultural activity and large number of production systems are in practice in different parts ofthe country. In pre-independence era (before the 1950s), agriculture in India was a system of harnessing nature for the sustenance of human beings, similar to the presently defined organic farming. Some countries have moved away from inorganic to organic farming yet it is not possible for India to depend entirely upon this system of farming due to large population. Total availability of plant nutrients from organic sources is projected to be 7.75 million tonnes by 2025 (Tandon, 1997) against the total requirement of37.50 million tonnes (Katyal, 2001) for 1504 million population (Sekhon, 1997). Thus nutrients supply through organic sources alone would result in deficiency of about 30 million tonnes of nutrients. Hence, it is imperative to use both organic and inorganic sources of plant nutrients enhance food production for the increasing population (Mahajan et al., 2007). In India the contribution of organic sources was 80-100 per cent in 1949-50 and reduced to about 32 per cent in 1993-94 and 20-25 per cent in 2004-05. So, it is imperative to enhance organic sources to meet total nutrient consumption. Following independence, rapid population growth in India placed great pressure on land and on these traditional farming systems; huge demands for food grains led to increased use of fertilizers and pesticides to boost production. Still a negative balance of about 8 million tones of NPK is foreseen in 2020, even if we continue to use chemical fertilizers, maintaining present growth rates of production and consumption. The most optimistic estimates at present, show that only about 25-30 per cent nutrient needs of Indian agriculture can be met by utilizing various organic sources. Many of the gains in production during the last 4-5 decades resulted from the “Green Revolution,” a campaign of technological interventions in agriculture widely adopted by farmers in developing countries. Expansion of irrigation to cover rain fed areas, popularization of hybrids/ transgenic varieties of crops, and use ofsynthetic chemical fertilizers and pesticides were the maj or technologies promoted. This paid rich dividends in India, quadrupling food grain production from 50 million metric tons in 1950-51 to 211 million metric tons in 2001-02, and enabling India to become self-sufficient in food grain. Now a second green revolution is also in the offing, to boost agricultural production and meet the estimated requirement of 337 million metric tons.

Indian horticulture has shown impressive impact on production, productivity and profitability. Currently, the total production of horticultural produce is 214.7 million tones from the 9% of total cultivated area in India, which contribute 30.4% to GDP of agriculture (Singh, 2010). In world perspective, India is second largest producer of fruits (68.5 mt) from 6.10 m ha area and contributes 11.2% in global fruit production. Vegetable crops occupying 8.0 m ha have the production of 129.1 mt (Table 1). However; India is the largest producer, consumer and exporter of spices and spice products in the world and produce more than 50 spices. The spice production in India is the order of 4.14 mt from an area of about 2.63 m ha. India is also the leading producer of plantation crops in the world and contributes 22.34% in coconut, 25% in cashewnut and 55% in arcanut. Commercial floriculture sector has recorded fast pace of growth during the last decade. During the last decade area under floriculture has expended to 1,67,000 ha with production of 9,87,000 MT of loose flower and 4.8 million cut flowers (Singh, 2010). The over all percent share of fruits and vegetables to their total production and contribution of different states for production of fruits and vegetables are repicted in Fig. 1 & 2. From the above fact, it is indicated that the production of horticulture produce has increased manifold but the gap in demand and supply continues simultaneously and is hardly sufficient and meets only 46% of national demand. Hence, there is a strong need to increase the production and productivity through crop diversification.

Protected cultivation of horticultural crops offers the best choice for diversification from traditional agriculture production system for a number of reasons. Production of crops under protected structures has great potential in augmenting production and quality of vegetables, flowers and in some fruit crops in main and off-season and maximizing water and nutrient use efficiency under varied agro-climatic conditions of the country. This becomes relevant to growers in India who have small land holding. They would be interested in a technology, which helps them to produce more crops each year from their land, particularly during off-season when prices are higher. The commonly protected structures are polyhouses, poly-tunnels, floating row covers, clotches, shade-net, insect-proof net and plastic-mulches (Chandra et al., 2000 ; Singh et al. 2010). These protected structures act as physical barrier and play a key role in integrated pest management by preventing spread of insect-pests and viruses which causes severe damage to the crop (Singh et al., 2003). This technology has great potential especially in periurban agriculture in near future, since it can be profitably used for growing high value vegetable crops like tomato, cheery-tomato, coloured peppers, parthenocarpic cucumbers, cut-flowers like rose, carnation, Berbera, lilium and fruits like strawberry, grapes etc. and for off-season cultivation of vegetables and their healthy and virus-free seedling production.

Protected cultivation is intended to mean some level of control over plant micro-climate to alleviate one or more of abiotic stresses for optimum plant growth. The microclimatic parameters being referred here are temperature, light, air-composition and the nature of rooting medium.

India is a leading vegetable producing country in the world. Presently it occupies 7.981 million hectare area with the annual production 129.077million tones (2008-09). The country being belessed with the unique gift of nature of diverse climate and distinct seasons, make it possible to grow an array of vegetables number exceeding more than hundred types. However, potato being the staple food and easy to mix in several preparations ranks first (26.6%) in total production of vetetables followed by onion (10.5%) and other important Solanaceous vegetables like tomato (8.6%), brinjal (8.0%). Cauliflower and cabbage are most preferred winter vegetables and their total share in the country’s vegetable production is 5.1 and 5.3%, respectively. Other important vegetables, which are primarily grown in the country, are okra, onion, vegetable peas and a good range of cucurbits (Fig. 1)

There is miss-match in area production and productivity of vegetables among various states of the country. The West Bengal ranks first in the total production of vegetables in the country and its production during the year 2008-09 was in tune of more than 22.704 million tones, contributing the more than one-fifth of total country’s vegetable product ion. Uttar Pradesh, Bihar and Orissa in north India and Maharashtra, Tamil Nadu and Karanataka in south India are the other leading vegetable producing states in the country. In last one decade, there has been considerable progress in enchancing the productivity of vegetables which is presently 16.2 tonnes hectare^-1. Incessant growth of urbanization, ceaseless fragmentation ofland holdings and depleting natural resources are the major challenges before the expansion of any agricultural commodity either cereals or vegetables. Hence, our attention must be focused on vertical expansion strengthened with the boon ofthe technology instead of horizontal expansion just by increasing the crop area. To ensure the nutrition security of the burgeoning population of the country, it is estimated that up to 2020, the country’s vegetable demand would be around 155 million tones (Rai et al., 2004; Pandey et al., 2009). To achieve this target, it is sine qua non to integrate the various technologies right from production to post-harvest.

The apparent reasons for undesirable productivity under intensively cultivated areas are depletion of native nutrient reserves, emergence of multinutrient deficiencies, and consequent decline in factor productivity of applied nutrient (Dwivedi et al., 2006; Yadav, 1998; Yadav, 2003). Surveys conducted at PDFSR in different agro-climatic regions of Indo- Gangetic Plain indicated that in order to achieve previously attained yield levels, farmers have started applying greater doses of N than the recommended ones (Dwivedi et al., 2001; Sharma, 2003). Such indiscriminate use of N is likely to further worsen the nutrient imbalance in soil-plant systems, besides increasing the pest incidence, cost of production and environmental problems (Dwivedi et al., 2001). The annual productivity of rice - wheat could hardly exceed 9 t ha^-1 in the multilocation experiments on yield maximization (Dwivedi and Singh, 2011). On the other hand, long-term experiments (Singh and Mishra, 2010) and other studies indicate that crop productivity can be sustained with balanced fertilization, taking into account the emerging deficiencies of secondary and micronutrients (Tiwari et al., 2006)

Nutrient management is a major component of a soil and crop management system. It becomes even more important in intensive high yielding cropping systems because of the higher investments at stake. The SSNM is applying those concepts to areas within a field that are known to require different management options from the field average. Site specific nutrient management is a concept that can be applied to any field and any crop. Yet, it is most often thought of in relation to use of computer and satellite equipment, and does not require large farming operation. The technology tools certainly expand the capabilities for using site-specific management. This is really a “repackaging“ of management concepts that have been developed and promoted for many years.

Soybean [Glycine max (L.) Merrill] is the leading oilseed crop in the world. Its area and production are far ahead of other oilseeds at the global level (Table 1). The commercial cultivation of this crop in India started in the early 1970’s. Within a span of 4 decades its spread has been phenomenal and today it occupies around 9.67 million hectares with a production of about 10.22 million with an average productivity of around 1006 kg ha^-1 (DSR, 2010) (Table 2). It is now the fourth largest among field crops after rice, wheat and maize (GOI, 2007) in India and has become the leading oil seed crop surpassing groundnut and mustard and rapeseed. It is contributing nearly 37% to the total oilseeds produced in India. The central India comprising the states of Madhya Pradesh, Maharashtra and Rajasthan account for more than 95% of the total area under this crop. Chhattisgarh, Karnataka, Andhra Pradesh, Uttar Pradesh etc account or the bulk ofthe rest ofthe area. It is predominantly a rainfed crop with only about 3% of the total area getting some assured irrigation facility. Further, it is concentrated in areas which receive lesser rainfall in its early vegetative phase. A large number of crops have been replaced by soybean to a variable extent in its march towards achieving its present position. Badal et al. (2000) have reported that a large number farmers switched over to this crop from sorghum, groundnut, maize, cotton etc in the state of Madhya Pradesh owing to greater yield potential even under adverse conditions (Table 3). Further, it has become an integral part of several cropping systems including both intercropping and-sequential cropping systems in different parts of the country.

The population of India is estimated to touch 1.4 billion by the year, 2025, which will need at least 300 million tonnes of food grain. This necessitates the production of additional food grain from the same land without loosing the production potential of the soil. This, in turn, requires extensive research to provide a scientific basis for enhancing and sustaining food production as well as soil productivity with minimum environmental degradation. In order to attain this it is essential that the amount of nutrients removed from the soil should be replenished through judicious use of fertilizers and manures. This needs a more comprehensive approach for fertilizer use, incorporating components like soil test, field research and economic evaluation ofthe results. Soil testing is one of the best scientific means for quick and reliable determination of soil fertility status. Soil test crop response study in the field provides soil test calibration between the level of soil nutrients as determined in the laboratory and the crop response to fertilizers as observed in the field for predicting the fertilizer requirements of the crop.

Objectives of soil testing.

Soil testing provides a sound information about the suitability, fertility and productivity of the soil. This enables the farmers to make the most profitable use of some of the costly inputs in farming. However, lack of information among the farmers about soil testing and their importance in management of resources necessitates that the work of soil testing should be taken extensively. Soil testing is a useful tool for making fertilizer recommendations for various crops and cropping sequences as well as reclamation of problem soils. Thus the major objective of soil testing are to identify the type of soil related problems like salinity, alkalinity, and acidity and to suggest appropriate reclamation/amelioration measures and to evaluate the fertility status in terms of available nutrients for making soil test based fertilizer recommendations.

Oilseeds serve as rich source of food, feed, energy, employment and commerce. The productivity of oilseeds in India (1006 kg ha^-1 during 200809) is very low when compared with the world productivity (1878 kg ha^-1 during 2008). The oilseeds production in the country often sufers from a high degree of variation in annual production owing to their predominant cultivation under low and uncertain rainfall situations which is further handicapped by input starved conditions with poor crop management. Nutrient and water are the key inputs for crop production. Improving efficiency and factor productivity under complexities of diminishing quality resources and increasing ecoawareness are critical for sustainable oilseeds production.

The vegetable oils consumption in the country is steadily rising and has sharply increased in the last couple of years touching around 14.1 kg head^-1 year^-1 during 2009-10. As per DAC-Rabo Bank, India’s per capita consumption is likely to reach at least 16.38 kg year^-1 by2020 and for a projected population of 1331 million, vegetable oil requirement will be 21.8 million tonnes. This is equivalent to about 66 million tonnes of oilseeds assuming that there is no change in the proportion of different oilseeds produced in the country in the next ten years. Assuming about 20% of vegetable oils contribution from sources like ricebran, cotton seed, coconut, oilpalm, etc., still the country needs to produce about 55 million tonnes of oilseeds by 2020. Considering that the oilseeds production during 2008-09 was just 27.56 million tonnes, the country needs to double oilseeds production in next 10 years requiring a growth rate in excess of 6%

Rice-wheat is a dominant cropping system in the Indo-Gangetic Plains covering approximately an area of 10.5 million ha. Modern agricultural production practices have emphasized the widespread use of fertilizers as a source of nutrients. The continuous use of high levels of chemical fertilizers over a prolonged period, decline in area under legumes and reduction in the use of organic manures has resulted in soil degradation and environmental pollution. It is estimated that the gap between nutrient removal by crops and addition through fertilizers in India will remain at level of 8-10 million tones per annum. Such negative nutrient balances are depleting the soils of their nutrient reserves resulting in acute deficiencies of nutrients. Integrated plant nutrient supply (IPNS) is an important component of sustainable agricultural intensification. The goal of integrated nutrient management (INM) is to integrate the use of all natural and man-made sources of plant nutrients, so as to increase crop productivity in an efficient and environmentally benign manner, without diminishing the capacity of the soil to be productive for present and future generations. The INM is made up of components which possess great diversity in terms of chemical and physical properties, nutrient release efficiencies, positional availability, crop specificity, and farmers’ acceptability. Since organic manures cannot meet the total nutrient needs of modern agriculture, integrated use of nutrients from fertilizers and organic resources seems to be a need of the time. For INM to make desirable progress and find wide acceptance, nutrient supply packages for important agroecological environments need to be developed. These should be technically sound, practically feasible, economically attractive and socially acceptable. Integrated plant nutrient systems can ensure long-term sustainability of agricultural growth through improvement in soil health and will significantly reduce the needs for chemical fertilizers. The complementary use of chemical fertilizers and organic fertilizers may increase the efficiency of chemical fertilizers in order to maintain a high level of crop productivity. Because of low primary nutrient content and thus the need for large applications per unit area, farmers and policy makers are often reluctant to adopt and promote the use of organic fertilizers. The different components of INM possess great diversity in terms of chemical and physical properties and nutrient release patterns.

Food security, nutritional security, sustainability and profitability are the main foci ofpresent agricultural scenario in India. In the absence of additional land for bringing under plough vertical growth in agriculture through intensive cropping and enhanced productivity becomes inevitable. Intensification of agriculture to meet the growing needs of the burgeoning population has brought with it numerous productivity related constraints. It has triggered multiple nutrient deficiencies in soil and this has raised doubts on the soils capacity to sustain anticipated production levels. One of the key inputs in enhancing and maintaining the productivity ofintensified agricultural systems is chemical fertilizer which provides nutrients in readily available form. But long term experiments on various cropping systems at various agroecological regions and soil types revealed that continuous use of chemical fertilizers in unbalanced and indiscriminate manner deteriorates the soil health and leads to deleterious effect on long term soil fertility and yield sustainability. Apart from the soil productivity issue, the use of chemical fertilizer is also becoming more and more costly due to scarcity during peak demand. The excessive use of chemical fertilizers is not only costly but they pollute the production environment (Singh et al., 2005; Dwivedi et al., 2003).

In the coming decades, a major issue in designing sustainable agriculture system will be the management and rational use of organic inputs such as animal manure, green manure, crop residues and biofertilizers etc. (Powlson, 1994). Long term studies indicated that current fertilizer recommendations are inadequate for maintaining yields (Bhandari et al., 2000; Singh and Mishra, 2010; Tiwari et al., 2006). It is, therefore, to sustain high crop yield without deterioration of soil fertility it is important to apply required amount of plant nutrients through fertilizers in combination with organic sources, crop residues, biofertilizers etc.

Post independence era brought about a radical change in agricultural scenario which improved economy and living standard of Indian farmers to a great extent. Green revolution, (field crops) during early sixties followed by white revolution (milk) and thereafter yellow (oilseeds) and blue (fish) revolutions made the country not only self sufficient in most of the food commodities but also exporter in many. Several calamities including droughts, floods, and ill effects of national and international conflicts faced by the, people of the country during post independence era could not affect the economy and stability of the country much because of rich agricultural heritage. As usual, the rapid and rather un-planned development creates several problems and this was true in our conditions too. Loss ofindigenous land races, depletion of soil nutrients and water resources, creation of salinity and water logging, resurgence of pest and diseases, declining factor productivity and farm profits and increased environmental (air, water & soil) pollution are among such problems have great concern to agricultural scientists and planners in coming future. The situation further aggravated because of industry oriented government policies and globalization which supported growth of industries and trades rather than agriculture and hence the growth rate in these sectors was considerably high. This fact is more visible by the figures on relative contribution of different sectors in the national GDP during last sixty years (Table 1). At the time of independence of the country more than 75% people were depend on agriculture related occupations which came down to mere 67.4% in 2009-10. Similar is the case of total contribution of agriculture in national GDP which decreased from 57% in 1951-52 to as low as 14.6% in 2009-10. Besides government policies, major factor identified responsible for degradation of resources, stability in production and decreased factor productivity is chemical based farming and that too in imbalanced and improper methods of application practiced by the farmers for getting more andinore production and profits per unit area per unit time The solution of this lies in the increased use of organic sources of nutrients in proper ratio along with chemical fertilizers - IPNS (Integrated Plant Nutrient System). Livelihood of marginal and small land holders who represent a large section (more than 86%) of farming community and remained deprived of advancements in the, field of agriculture has been the main agenda of the Indian Government in Xlth, five year plan and to continue in Xllth plan too. To ensure livelihood improvement with focus on small and marginal farmers Integrated Farming System (IFS) has been proved to be an effective approach. Accordingly, the Project Directorate of Cropping Systems Research renamed as Project Directorate for Farming Systems Research with AICRP on Integrated Farming Systems Research and Network Project on Organic Farming mandated with farming systems perspectives. Since, integrated farming system is a holistic approach wherein all the wastes and residues are recycled within the system and nothing go waste. Output of one enterprise is used as input for the others. This way, farming becomes more economic and environmentally safe.

Sustainable agriculture warrants a wise management of natural resources and inputs to satisfy human needs in the fast changing scenario while maintaining, if not improving, the quality of environment. Soil as a natural resource is facing more and more serious degradation threats under modern agriculture. Incidence and expansion of multi-nutrient deficiencies in Indian soils owing to inadequate and unbalanced nutrient input through fertilizers is considered one of the major reasons for decline in factor productivity of crops. The problem of soil fertility depletion is spectacular across the soil types and agro-climatic zones, but it is more acute in intensively cropped areas, where annual nutrient removal by the crops often far exceeds replenishments. Recent diagnostic surveys indicate that in several high productivity areas of irrigated ecosystems like, Trans-and Upper Gangetic Plain zones, farmers are resorting to even excessive use of fertilizers, especially N, to maintain the yields at levels attained previously with lower fertilizer application rates. With an unabated deterioration in soil health in general, and soil fertility in particular, and a mounting pressure on finite land resources due to increase in population, the interest in soil fertility and soil health has revived due to several reasons:

Stagnation in growth rates of production and productivity of staple foodgrains - threat to food security

Decline in factor productivity, thus increasing cost of production

Nutrient withdrawals in excess of replenishment

Low nutritional value of food and feed grown on nutrient-starved soils - threat to nutritional security

Poor quality of produce fetching low price - threat to economic security

Limited availability of additional land for crop production, along with declining yield growth for major food crops, have heightened concerns about agriculture’s ability to feed a world population expected to exceed 7.5 billion by the year 2020. Decreasing soil fertility has also raised concerns about the sustainability of agricultural production at current levels. Future strategies for increasing agricultural productivity will have to focus on using available nutrient resources more efficiently, effectively, and sustainably than in the past. Management of the nutrients needed for proper plant growth, together with effective crop, water, soil, and land management, will be critical for sustaining agriculture over the long term. Plants, like all other living things, need food for their growth and development. Growth is the function of various factors like light, carbon dioxide gas, water and mineral nutrients. Plants require 16 essential elements. Carbon, hydrogen, and oxygen are derived from the atmosphere and soil water. The remaining 13 essential elements (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, zinc, manganese, copper, boron, molybdenum, and chlorine) are supplied either from soil minerals and soil organic matter or by organic or inorganic fertilizers. For plants to utilize these nutrients efficiently, light, heat, and water must be adequately supplied. Cultural practices and control of diseases and insects also play important roles in crop production. Each type of plant is unique and has an optimum nutrient range as well as a minimum requirement level. Below this minimum level, plants start to show nutrient deficiency symptoms. Excessive nutrient uptake can also cause poor growth because of toxicity. Therefore, the proper amount of application and the placement of nutrients are important.

All the states have some area under irrigation. Thus the term ‘irrigated ecosystem’is rather loosely defined, and the states having distinctly large net irrigated area may constitute this ecosystem. Two such areas can be easily carved out i.e., Indo-Gangetic Plain region representing five states namely Punjab, Haryana, U.P., Bihar and West Bengal, and coastal areas of two southern states i.e., A.P and Tamil Nadu. About 56% of the net irrigated area of the country exists in these states, and the cropping intensity is also much higher (144%) as against national average of 132%. With demographic viewpoint also, these areas are densely populated. Of late agriculture in this ecosystem has become unsustainable owing to over-exploitation of natural resources. Studies have conclusively established the superiority and worth of integrated nutrient management in restoration of soil health and sustenance of crop productivity and profits.

The basic concept underlying the principles of integrated nutrient management (INM) is the maintenance, and possibly improvement, of soil fertility for sustaining crop productivity on long-term basis. This may be achieved through combined use of all possible sources of nutrients and their scientific management for optimum growth, yield and quality of different crops and cropping systems. INM is not a new concept, but an age-old practice. Its importance was, however, not realized earlier due to low nutrient turn over in soil-plant system and almost all the nutrient needs were met through organic sources, which supplied secondary and micronutrients also besides major nutrients. INM has now assumed great significance mainly because of two reasons. First, the need for continued increase in agricultural production based on increase in per hectare yields requires growing application of nutrients, and the present level of fertiliser production in india is not enough to meet the total plant nutrient requirement. Second, the results of a large number of experiments on manures and fertilisers conducted in india and other countries reveal that neither the chemical fertilisers alone nor the organic sources exclusively can achieve the production sustainability under intensive cropping systems (Hegde and Dwivedi, 1993). Even the so called balanced use of chemical fertilisers would not be able to sustain high productivity due to emergence ofthe deficiencyofone ormore ofthe secondaryandmicronutrients (Swarup and Wanjari, 2000). The interactive advantages of combining organic and inorganic sources of nutrients in INM have proved superior to the use of its each component separately. The advantages of INM can be broadly enumerated as following:

Rice-wheat (RW) is the major cropping system occupying about 10.5 mha in the IGP of India. It contributes more than 60% of the foodgrains to the central pool. With shrinking land resources and burgeoning population, the RW system will be under pressure to produce more grain output per unit area in the coming decades. Meeting this challenging task requires sustainable management of soil, water and plant nutrient resources. High yields of the irrigated RW system result in production of huge quantities of crop residues. Total production of crop residues in Punjab is about 47.2 mt which includes paddy straw, wheat straw, cotton sticks, sugarcane leaves, maize stalk, and other oilseeds and pulse residues (Beri and Gupta, 2003). Wheat and rice straw constitutes more than 70% ofthe crop residues produced in the country. Paddy straw alone constitutes more than 50%. Cotton and sunflower residues are generally used as fuel. Sugarcane trash (leaves) is generally burnt in-situ or used as fuel after collection from the field. Increasing constraints of labour and time have led to the adoption ofmechanized farming in the highly intensive RW cropping system. Approximately 91% ofthe total rice area is mechanically harvested, while 82% of the total wheat area is mechanically harvested. Traditionally, wheat and paddy straws have been removed from the fields for use as cattle feed and for several other purposes such as livestock bedding, thatching material , for houses, and fuel. While more than 80% ofwheat residue is collected by the farmers after combine harvesting and often fed to animals, paddy straw is considered poor feed for animals due to its high silica content.

Substantial loss ofplant nutrients (especially N and S) and organic carbon occurs during burning of crop residues, with important implications to soil health. About 40% of the N, 60-85% of the K, 30-35% of the P, and 40-50% of the S absorbed by rice remains in the vegetative parts at maturity. One tonne of paddy straw contains approximately 6-7 kg of N, 1.0-1.7 kg of P₂O₅ and 14-25 kg K₂O. Apart from huge loss of precious plant nutrients, burning of crop residues depletes soil health. Air pollution from stubble burning also impacts human and animal health both medically, and by traumatic road accidents due to restricted visibility. In view ofthe serious problems associated with the residue burning, new ways are being sought to efficiently utilize the huge amount of surplus residues produced in the country.

With the advent of modern crop varieties, better irrigation facilities and greater use of fertilizers and other inputs country has changed within the last 50 years from a region of food scarcity to a region of food sufficiency. The greenrevolutiontechnologiesinvolvinggreateruseofsynthetic agro-chemicals such as frrertilizers and pesticides with adoption of nutrient- responsive, high yielding varieties of crops have boosted the production per unit area under different crops and cropping systems. However, this increase in production has slowed down and in some cases there are indications of decline in growth of productivity and production (Table 1). These production scenarios may be envisaged as corresponding decrease in soil organic matter and continuous increase in multi nutrient deficiency (Dwivedi et al., 2006). If such situation is allowed to continue for another few decades, there are chances that todays’ productive land may become unproductive. The declines in yield and production fatigue have been noticed in various cropping systems of different agro-eco region (Gill and Singh, 2009). Farmers’ participatory surveys conducted in Indo-Gangetic Plain (IGP) region indicates that farmers’have resorted higher doses ofnutrients each year to obtain the same yield as obtained in previous year (Dwivedi et al., 2001). The probable reasons behind these are continuous mining of nutrients, inadequate use of organic sources, imbalance fertilization and decline of soil organic matter.

During the last 50 years or so, the world has witnessed tremendous changes in terms of population exodus, accessibility to food, advancement in agricultural science and technology, increased food production, efforts in mitigating food and nutrition security, natural and human made disasters and developmental efforts in handling and containing national and global issues. Inspite of these efforts, the challenges which have cropped up are plenty and at the same time creating avenues of opportunities to address those challenges in the interest of humanity. The world is large, countries are many, agro- climatic regions vary significantly, socio-economic conditions are distinct and the national, regional and global issues vary greatly. For ease of presentation and convenience of illustration, common issues only will be dealt in this chapter. Keeping in view the theme of this book, the following topics/issues will be discussed which pose challenges for the living humanity and for future generation within next 50 years. The views are limited to developmental, planning and implementation processes only in order for governments and others to consider overcoming these challenges.

SYNOPSIS

This millennium has brought about serious challenges as well as excellent opportunities for the betterment of humanity. The migration of rural population to urban areas is one of the major challenges foreseen. It is expected that much of the population growth is expected to take place in the cities of the developing world. By 2020, about 52 percent of the developing world’s population will be living in urban areas (IFPRI, 1999). The agricultural areas around cities offer great promise to urban and peri-urban agriculture.

The interventions on Urban and Peri-urban Agriculture (UPA) suggested and initiative undertaken by FAO is timely and valuable in the interest of the teeming population demanding for both nutrition and health. The International Conference on Vegetables (ICV-2002) held during 2002 has emphasized the importance of vegetables; FAO International Workshop on Urban and Peri-urban Agriculture for Asian Countries organized during 2005 had amply emphasized the important role of horticulture; and the International Conference on Horticulture (ICH-2009) held during 2009, has amply illustrated the importance of horticultural crops particularly vegetables in UPA for the benefit of urban population.

The urbanization process is a reality that drives people to go and live in the cities. It is very pronounced in Latin America where already 85% of the population lives in cities; in Asia the average is reaching 60% whereas in Africa the phenomenon has started later and has now reached 35%. Besides the increased demand for food, there has been a rapid increase of poverty, unemployment, hunger and malnutrition in the Urban and Peri-urban environment around the world that are of great concern to central and municipal authorities.

UPA can contribute to feeding the urban population, generate income and employment and thereby reduce poverty. In reality many countries have already UPA related activities going on in areas of horticulture including vegetables, dairy production, small livestock, aquaculture and forestry. However, it has been realized that very few countries had actually investigated the real opportunities and constraints linked to the urban agriculture sector.

Keywords : Urban Agriculture, Urban Food, Peri-urban Agriculture, UPA.

1. INTRODUCTION

India is principally an agricultural country with seventy per cent of its population living in villages and fifty nine per cent of the total work force dependent on agriculture for its daily bread. Almost 20% of the gross GDP is contributed by agriculture. A steep surge in production since late 1960s has made country self-reliant in food grain production with buffer stocks full to the brim. Since independence, 0.66% growth/ year in gross agricultural area combined with 2.67%/year increases in food grain production led to a net increase in per capita food grain availability from 395 g/ day to 475 g/ day. An outstanding achievement, as it happened despite an unabated population build up at a rate of 2.15 %/ year or 13 million more mouths to be fed every year. Not only in food grain production, the country has made revolutionary progress in milk, fish, eggs, fruits and vegetable production also (NAAS, 2004).

Needless to say that the economic growth of our country depends largely on the prosperity of the agriculture. The agricultural sector acts as a bulwark in maintaining food security as well as national security. The first and the foremost role of agricultural is its promotion of economic progress in the country by enlarging the savings of the rural sector and making them available for the development of industries. Gandhiji, the father of the nation called “Agriculture as the soul of India”. Also, agriculture has been termed as “The mother of all industries and the maintainer of human life standing at the need of all sciences and arts, indeed, at the head of civilization and progress”. The significance of agriculture in India arises also from the fact that the development in agriculture is an essential condition for the development of the national economy. Thus any change in the agriculture sector- positive or negative- has a multiplier effect on the entire economy (Rekha & Rangappa, 2010).

Over 70 years ago, Mahatma Gandhi made the following observations while addressing youth who wanted to serve rural India:

‘The fact is that the villagers have lost all hope. They suspect that every stranger’s hand is at their throats and that he goes to them only to exploit them. The divorce between intellect and labour has paralyzed our agriculture. The worker should enter a village full of love and hope, feeling sure that where men and women labour unintelligently and remain unemployed half the year around, he working all the year round and combining labour with intelligence cannot fail to win the confidence of the villagers’.

This message is as relevant today as it was 60 years ago. Integrating brain and brawn in farm enterprises should hence be the purpose of agricultural education. (ICAR, 1997)

SYNOPSIS

Until recently, agriculture was primarily valued for producing staple cereals. Today, there is increasing recognition that agriculture has an important role to play in improving nutrition, human health and environmental health. Helping agriculture successfully forge links with nutrition and health can enable the research, development and policy communities to more effectively address the looming challenges of hunger, malnutrition and agriculture-associated diseases. Already, there is growing momentum around the world to bring these sectors together to improve food and nutrition security of the world’s poorest people.

Keywords : Food security, nutrition, health, agriculture.

1. INTRODUCTION

During the past fifty years, the world has made substantial progress in improving the food security of millions of people. Using science and technology, agricultural extension and appropriate policies and incentives complemented with infrastructure, farmers, researchers and policymakers have worked together to increase the global production of cereals, cutting the proportion of hungry people from approximately one-third to one-sixth of the world population (Spielman and Pandya- Lorch 2010). Yet more needs to be done. Nearly one billion people still suffer from hunger. Micronutrient deficiencies affect billions more today and potentially in the long-term. Malnourishment in children’s first two years of life, for example, causes largely irreversible damage, impeding their physical growth and intellectual development, increasing their susceptibility to diseases such as diabetes and cancer and even drastically reducing their incomes as adults. Undernourished women are more likely to give birth to smaller babies, thereby creating an inter- generational trap of under nutrition and poverty.

While agriculture has traditionally been put to work to raise the productivity and production of staple crops, there is increasing recognition that agriculture is also key to improving nutrition security, individual health and environmental health. This nuanced understanding has come just in time, considering the looming challenges of hunger, malnutrition, climate change and its link to energy and resource scarcity and urbanization. Placing agriculture in this larger context may enable the global community to better address and cope with these challenges, whilst meeting the food and nutrition security needs of the world’s most vulnerable people.

This paper will briefly review the evolving role of agriculture in meeting food and nutrition security. It will identify emerging challenges, describe promising developments and highlight opportunities for leveraging agriculture-nutrition-health links to overcome challenges.

1. INTRODUCTION

The paradigm of world’s livelihood is built on the basic foundation of natural resources which includes humans, plants, animals, soils and minerals, water and air. But the very livelihood of these resources are at stake because they are strongly linked and dependant on each other. And to add, the material resource namely ‘economy’ has invaded the tranquil habitat and life of the community of natural resources. Thus the present crisis is challenging livelihood of each of these natural resources whether it is human, plant or water or earth and the element of economy is interfering with the natural recourse of human depending on water and soil; and human, plant, animal together are depending on soil, water and air. But when the livelihood of soil, water and air is at stake how human, plant and animal can survive; hence the design of livelihood of world has the essential ingredients of all natural resources.

We humans are selfish and concerned about our livelihood security only and try to over-exploit other natural resources and assumed themselves as the master of all natural resources. Practically, there is war going on between and among natural resources. The world could be better if each natural resource has its own right with prospects to safeguard its livelihood and all resources together with better livelihood could offer the lively world.

2. UTILIZATION OF NATURAL RESOURCES

We should underscore that none of the natural resources are in ‘plenty’ and that we should ‘economize’ on each natural resource to build together the world’s livelihood. The food security of humans can not be attained without plants and plant security can nor be achieved without soil and water and it is impossible to keep secured soil and water without economics of management.

In short, the livelihood security of humans is entirely dependant on all other natural resources coupled with the material resource economy. It is incumbent on us to initiate appropriate steps from gross root to policy levels to make the world better.

1. INTRODUCTION

It is hard to conceive which came first on earth, human being or food. If the human was born first, he or she needed food immediately to survive. Thereafter, the human beings continued to need food and continued to eat food throughout his or her life. Hence, the relationship between human being and food is permanent and the requirement of food for the human being to be alive is everlasting. Further, sources of food may survive in nature without human intervention but human being can not remain alive without food. This clearly signifies the permanent bondage of human being and food which is inseparable under any circumstances. ‘Thus, should we state that every human being necessarily needs food and should have right to food as soon as born.

In order to further strengthen this view, the governance which rules human beings should also be protective and enact laws to ensure food to each human being born in respective countries.

2. BACKGROUND

•   “Hunger is exclusion”, wrote de Castro (1963) a Brazilian anti-hunger advocate. “Exclusion from the land, from jobs, wages, income, life and citizenship. When a person gets to the point of not having anything to eat, it is because all the rest has been denied. This is a modern form of exile. It is death in life”.

•   Simply by being born, everyone has the right to food. A person doesn’t have to do anything to “deserve” it; the right to food is a birthright. But this does not entitle a person to sit back and ask for free food. People are responsible for doing all they can to realize their own right to food. Governments that are parties to the International Covenant on Economic, Social and Cultural Rights are responsible for ensuring that all those living within their borders have the means to do so, (FAO, 2007).

•   Broadly speaking, governments should create peaceful, stable, free and prosperous environments in which people can feed themselves in dignity. Even without a legal obligation to do so, countries have a moral obligation to ensure freedom from hunger (FAO, 2007).

Food is basic to human being and agriculture is the catalyst between the two which is basically supported by natural resources. The human being is entirely dependant on food and food is fully dependent on agriculture and humanity. Eventhough food, agriculture and humanity have their own entity; they are inseparable for the survival and existence of each other. Hence, the three pillars of food, agriculture and humanity forming a triangle symbolize the roots of human civilization.

I find myself fortunate to have the opportunihj to live and experience the working life of the farmers and the farming in Kansas (USA), Nigeria (Africa), Saudi Arabia and Yemen (Middle East), Italy (Europe) and India, Myanmar and Thailand (Asia). It zvas fiirther strengthened by visits to farmers in another about 100 countries. Day after day and month after month and even years, it made me to realize that community culture, language and farming in each state, country and continent are different from each other but some things are common and that they are all doing farming, they are growing food and they all doing for the livelihood of their families, neighbors and communities near and far (Nath, 2011).

The foundation of agriculture is laid on available natural resources e.g. land, water, sunlight, air, plant, animal and human beings. The human beings, being the leader to manage the resources have contributed to redefine agricultural science and promote and develop technology. This has led to augment agriculture and its science and technology. At the end, the human efforts have brought about changes and improved agriculture production at the cost of excessive use of natural resources, knowing well that without natural resources, without good soil and water hardly anything will survive.

Presently world produces enough to feed the present human population, but it is not available to millions of people. It is not the lack of availability of food but is the unequal distribution and lack of entitlement which are causing hunger and malnutrition in millions of population.

Introduction of Food Industry

India is one of the major food producers in the world. The food sector contributes to about 28% of India's GDP. India stands at 1st position in the world for production of cereals, milk, livestock, banana and Mango, 2nd in producing fruits and vegetables and ranks amongst top 5 in producing rice, wheat, groundnut, tea, coffee, tobacco, spices, sugar and oilseeds. India's share in global production of fruits is 10% and vegetables are 13.7%. The current consumption of fruits and vegetables is approx Rs.2 lakh crores at current prices with an estimated growth rate of 11% per annum. The growth rate is higher than cereals and milk and comparable to meet consumption

Status of Food Processing Industry

The food processing industry in India is still in a sorry state. The rural population comprising 70% including small cities, consume less than 10% of the processed foods and vegetables, whereas 60% of the processed food is consumed in four major metropolitan cities and 30% in the state capitals and big cities. Another fact is that 40% of the processed food and vegetables produced in the country in terms of value are bought by institutional buyers like Hotels, Restaurants and Defense etc. The highest growth in domestic market has been in fruit drinks, tomato ketch up and Jams.

There is another fact that India is the largest milk producer in the world, however, organized industry accounts for less than 15% of the milk produce in India. It is estimated that there may be a total production of 1100 million tons of production of food products mainly food grains, oilseeds, sugarcane and fruits/vegetables during 2011-12 and leaving marketable surplus of 870 million tons.

Purpose of Law

The Food Laws or Regulations are made in order to protect people consuming these foods from undue risks, which may arise from processing, transport, retailing and consumption of food products which may undergo contamination, spoilage, inclusion of harmful chemicals/microbes or at harmful levels. Besides safety, consumers are also protected by these laws with respect to quality, quantity and substance that the food products are supposed to represent. Finally, laws also aim to protect the consumers from Nutrition and Health considerations with special consideration being given to vulnerable group such as infants, pregnant women etc.

Food additives are chemical substances added to foods to improve flavour, texture, colour, appearance and consistency or as preservatives during manufacturing or processing. Herbs, spices, hops, salt, yeast, water, air and protein hydrolysates are excluded from this definition.

In many countries, the use of food additives is regulated, and food additives must be declared on food labels by using their chemical names or numbers. the use of any new additive in a particular food, they ensure that:

Importance of Food Storage

Food storage is both a traditional domestic skill and is important industrially. Food is stored by almost every human society and by many animals. Storing of food has several main purposes:

•Storage of harvested and processed plant and animal food products for distribution to consumers

•Enabling a better balanced diet throughout the year

•Reducing kitchen waste by preserving unused or uneaten food for later use

•Preserving pantry food, such as spices or dry ingredients like rice and flour, for eventual use in cooking

•Preparedness for catastrophes, emergencies and periods of food scarcity or famine

•Religious reasons (Example: LDS Church leaders instruct church members to store food)

•Protection from animals or theft

Definition

Packaging is the science, art, and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of design, evaluation, and production of packages. Food packaging is packaging for food. It requires protection, tampering resistance, and special physical, chemical, or biological needs. It also shows the product that is labeled to show any nutrition information on the food being consumed

Packaging may be defined as co-ordinated system of preparing foods for transport, distribution, storage, retailing and their use. It is also a means of ensuring safe delivery of goods to the consumer in sound condition without affecting adversely the quality of the product packed in it at a reasonable cost. Packaging thus has as “techno-economic function” aimed at maintaining the quality of food stuff packed, with a view to retain the quality for a reasonable period.

Packaging plays a vital and dominant role in marketing, in maintaining quality and in preserving the food.

Consequent to the increase in the consumer awareness of the healthy hazards, which may be posed by different types of packaging material. It becomes inevitable for the packers to use better quality, hygienic packaging material which could retain the quality of the product for a longer time without posing any health hazard. The choice of a suitable packaging becomes all the more necessary for a number of factors like physico-chemical characters and acceptability of the commodities packed in any packaging material. Apart from this the package should be of the right shape and size and must attract the consumer's eye which could offer an absolute confidence regarding the wholesomeness of the products pack in it.

Importance of Food Additives

Food additives are chemicals, biochemical ingredients etc., which are added to food products for their technological benefits. These benefits may be to preserve the quality of food, to maintain and improve its appeal, to ensure its nutritional value and to provide innovations in new products with consumer appeal and satisfaction. Additives are also added to maintain uniform quality and to enhance quality parameters such as flavour, colour, texture etc. in large-scale production. They and their by-products ultimately become part of the food that is consumed and so they must be safe.

Additives may be direct additives, which are added deliberately to improve its sensory quality, nutritive value, stability, ease in processing and retention of quality during handling and retailing. There are also indirect additives, which are not added intentionally but get included into foods incidentally during handling, processing and packaging.

There are some guiding principles for the use of food additives. They should be justified for their technological effectiveness and purpose. They should be safe for use. There should be maximum adequate levels, absolutely necessary levels of usage and ADI (Acceptable Daily Intake) properly evaluated while considering its safety and permitted usage levels in foods. They should not be added with the intention of misleading consumers about quality. They should also not significantly affect adversely the nutritional quality of food products.

Importance

The dairy products, which have originated in India, are called indigenous dairy products. The products can be broadly classified in to khoa based and channa based. The importance of the dairy products were known to Indians since time immemorial or it could be roughly estimated to be around five thousand years ago and the development could be considered as an art.

Tamarind (Tamarindus Indica)

Introduction

The fruit of tamarind a pod 5 to 15 cm long, 3 to 10 seeds surrounded with edible pulp which is principal souring agent for sauces, chutney, in beverages and in general cooking. Pulp is carminative, laxative, given as infusion in biliousness and febrile conditions. It is also used in dyring and tanning and for polishing and cleaning metal ware. The tartaric acid is extracted from unripe fruits. The polysaccharide (jellose) is extracted from seeds, which is used as a sizing material in the cotton and jute industries. Besides, polyose obtained from the seed is good substitute for fruit pectin in the preparation of jam, jelly or marmalade. The bark and leaves are used for tanning. Tamarind balls are prepared after taking out seeds from the fruit. Tamarind paste and tamarind juice concentrate are the other commercial products.

The fruits, flattish, bean-like, irregulary curved and bulged pods, are born in great abundance along the new branches and usually vary from 2 to 7 in long and from 3/4 to 1 1/4 in (2-3.2 cm) in diameter. Exceptionally large tamarinds have been found on individual trees. The pods may be cinnamon-brown or grayish-brown externally and, at first, are tender-skinned with green, highly acid flesh and soft, whitish, under-developed seeds. As they mature, the pods fill out somewhat and the juicy, acidulous pulp turns brown or reddish-brown.

Introduction

The tropical root and tuber crops are comprised of crops covering several genera. They are staple foods in many parts of the tropics, being the source of most of the daily carbohydrate intake for large populations. These carbohydrates are mostly starches found in storage organs, which may be enlarged roots, corms, rhizomes, or tubers. Many root and tuber crops are grown as traditional foods or are adapted to unique ecosystems and are of little importance to world food production. Others such as cassava (Manihot esculenta Crantz) and white-fleshed sweet potato (Ipomoea batatas L.) are known worldwide. Several of these crops have been termed under-exploited and deserving of considerably more research input

Potato and Banana chips: Potato chips are one of the popular snack foods consumed throughout the country. Chips are mostly prepared by small scale artisans / confectioners, and sold in plastic film or paper packs. Recently, however some of the companies have installed plants having relatively large capacities and have started marketing chips in attractive packs. The fat content generally ranges between 25-40% and moisture content between 2-4%. Potatoes having high total solids, low reducing sugars and low amylase activity are most suitable for chips manufacture.

Banana chips are prepared from varieties rich in starch having very low levels of soluble sugars and polyphenol - oxidase activity. These are mostly processed and marketed in Southern States especially in Kerala. Previously, the chips were fried in coconut oil, but now other vegetable oils are also used in their processing. Relatively, banana chips are harder in texture than potato chips.

Importance of Fruits and Vegetables in Human Life

Fruit is the edible, and more or less juicy, product of a tree or plant and consist of the matured ovary including its seeds and adjacent parts. Usually fruits are sweet, with a wide range of flavours, colours and textures.

Composition

Fruits are very poor source of protein and fat. Avocado is the exception containing 28% fat. Fruits contain high amount of moisture hence they are highly perishable. They are also good source of fiber. Fruits are not very good sources of calories. Fruits like bananas give fairly good amount of calories. Ripe fruit contains a higher percentage of sugar than unripe fruit does and the sugar is chief in the form of sucrose, fructose and glucose. Generally fruits are poor source of iron, Mangoes are excellent source of carotenes. Oranges are fairly good source of beta carotene. Guavas are the best source of vitamin C. Citrus fruits are good source of vitamin C. Cashew fruits are inexpensive and rich in vitamin C, although there is variation of vitamin content from fruit to fruit most fruits in the raw state contain some ascorbic acid. If fruits are bruised, peeled, cooked or exposed to air, large amounts of the vitamin may be oxidized. Apples are not only expensive; they contribute little to the nutritive value. They give fiber to the diet.

Importance of Traditional Foods

Traditional convenience food, or tertiary processed food, is commercially prepared food designed for ease of consumption. Products designated as convenience foods are often prepared food stuffs that can be sold as hot, ready-to-eat dishes; as room-temperature, shelf-stable products; or as refrigerated or frozen products that require minimal preparation (typically just heating).

These products are often sold in portion controlled, single serve packaging designed for portability for “on-the-go” eating. Convenience food can include products such as candy; beverages such as soft drinks, juices and milk; fast food; nuts, fruits and vegetables in fresh or preserved states; processed meats and cheeses; and canned products such as soups and pasta dishes.

Traditional Foods

Preparation of Vadagam and Appalam

Vadagam is a traditional product mostly prepared from rice flour and also sago. It is an deep fat fried product and consumed as a side dish in the meals. Papad also known as appalam or papadam in South India, is essentially a thin wafer like product, usually circular in shape rolled from a dough made out of pulse, cereals, edible vegetable oil, alkaline and mucilaginous additives. It is normally consumed in toasted or fried form. In India, papad has been associated and deeply entwined with social customs/ rituals and has been developed into culinary art.

Importance of Foods

The word “instant” has been used in widely different types of premixes to specify the products either as ready-to-eat food or semi processed foods. The instant premixes available in Indian market were classified as Indian products and Westernized or sophisticated products. The instant mixes included under Indian market products are spice mixes, snack mixes and desert and sweet meat mixes. The Westernized products (instant mixes) contained soup mixes, beverage mixes, desert mixes and soft drink mixes.

Convenience foods are gaining popularity in recent years as they are very easy to handle, require minimum storage space and are attractive. Convenience foods have emerged as a new set of products in the international market. Most of the traditional foods that are commercially available in our country are being prepared / processed by cottage industries and by some of the multinational companies. The various types of convenience foods/ instant mixes that are presently being processed, marketed and consumed all over the country. Supplementation with protein-rich sources and preparation of acceptable ready-to-eat snack foods would not only correct its nutritional inadequacies, but would also provide a variety.

Instant mixes were high in nutritive value especially needed for armed forces, light in weight, easy to carry and prepare. Rapid industrialization and urbanization and changes in eating habits of Indian people led to very high demand for ready-to-use snack foods. The convenience instant foods are meeting the urgent and exigency situations of offering hospitality to unexpected guests.

Changing life styles and values are at the root of considerable changes in eating habits over the last few years. Hand-in-hand with a strong demand for fast and take away foods, there has been a marked upturn in popularity for convenience foods in India. The major reasons for this trend are: the decline of the family meal time, growth in disposal incomes (only in cases of city dwellers), the desire for more leisure time and demand for “foreign” or “sophisticated” dishes inspired by the media and increased travel.

Q fever (query fever) is an important global occupational zoonotic disease caused by a bacteria Coxiella burnetti. It is an OIE notifiable disease and showing an emerging and reemerging trend in different parts of the world. It is having great public health importance as the pathogen is transmitted through almost all routes but predominantly by aerosols from reproductive discharges of animals of farm and pet animals which serve as main reservoir of infection. The organism is shed in milk and foods of animal origin for very long period. Q fever is associated with a wide clinical spectrum and most of its acute infections are either asymptomatic, mild or resemble to influenza. Presently, the infection is endemic in many areas and its prevalence has been confirmed in at least 51 countries including India.

Etiology: C. burnetti was classified as a member of Rickettsiaceae family however, recent scientific investigations on 16S RNA based sequence analysis have shown that it is genetically more comparable to bacterial families covering genus Francisella and Legionella therefore it has been reclassified in the family Coxiellaceae or order Legionellales. It is a Gm-, pleomorphic rods (0.2-0.41μX0.4-1.0μ) or sphere (0.3μ-0.4μ in diameter in size) and an obligate I/C organism. It is relatively resistant to physical and chemical agents. The bacterium occurs in two antigenic forms - the pathogenic form (phase I) found in infected animals or humans and the avirulent form (phase II) obtained by repeated passagein embryonated eggs or in cell culture. Phase II cells are autoagglutinable and are readily phagocytosed in the absence of specific antibodies. Phase I activity is attributed to surface carbohydrate antigen which is soluble in trichloracetic acid and is destroyed by periodate. Phase I is a more powerful immunogen than phase II and elicits antibodies in high titer to both antigens. Phase II antigen gives better results in CFT with human and animal sera. Q fever sera do not react with other rickettsial antigens or with Proteus. In nature, bacterium exists mainly in 3 forms, namely - the small cell variant (SCV), the small dense cells (SDC) which are spore like forms that remain very stable in the environment as extracellular infections particles and the large cell variant (LCV) which is the growing and metabolically active form inside the host. In view of the potential for transmission of this infection from animal to people, the disease has been classified as a notifiable OIE disease.

It is a non-contagious, nonfebrile infectious disease of mammals caused by toxin of Cl. tetani and characterized by sposmodic contraction of skeletal muscles.

Etiology: It is caused by Cl. tetani. It is a Gm⁺, slender bacillus, 4-8μ X0.5μ in size. It has a straight axis, parallel sides and rounded ends. It occurs singly and occasionally in chains. The spores are spherical, terminal and bulging, giving the bacillus the characteristic 'drum stick' appearance. It is non-capsulated and motile by peritrichate flagella. Young cultures are strongly Gm+ but older ones may be Gm-. Cl. tetani is widely distributed in soil and in the intestine of man and animals. Soil may have good concentration O organisms if it is fertilized with animal manure. Some strains have been identified but they have same antigenic type of toxin and can be neutralized by single toxin. There are two types of antigen H (flagella) and O (somatic). The H antigen is thermolabile and O antigen is thermostable and responsible for spasms.

It is an obligatory anaerobe that grows only in the absence of O₂ It grows on ordinary media. Growth is improved by blood and serum but not by glucose. The spores are very much resistant and can persist in the soils for even years. The spores can be destroyed by boiling at 115°C for 30-60 min.

The organisms produce 3 types of toxins. The toxins are tetanospasmin (neurotoxin), tetanolysin (haemolysin) and fibrinolysin. Tetanolysin is a heat labile, O₂ labile haemolysin antigenically related to the O₂ labile haemolysin produced by Cl. welchii. This lysin is active against RBCs of several animal species. Tetanospasmin is responsible for clinical manifestation of tetanus. It is O₂ stable but relatively heat labile. It gets toxoided spontaneously or in presence of low concentration of HCHO. It is a good antigen and is specifically neutralized by the antitoxin. It exists in two forms. A monomer of MW 68,000 which is toxic and a dimer which is non-toxic but antigenic. The purified toxin is active in extremely small amounts and has an MLD for mice of about 50-75X10^-6 mg. Horse is the most susceptible animal. Guinea pig, mice, goats and rabbits are susceptible in that descending order. Birds and reptiles are highly resistant. Frogs which are insusceptible, may be rendered susceptible by elevating their body temperature.

Salmonellosis is one of the important zoonoses, acute or chronic in nature, affected by all species of animals, birds and humans and characterized by gastroenteritis.

Etiology: The genus Salmonella belongs to the family Enterobacteriaceae. Currently there are 2463 serotypes (serovars) of Salmonella. According to the current system used by the CDC the genus Salmonella contains two species each of which contains multiple serotypes. The two species are S. enterica, the type species and S. bongori. The S. enterica subsp. enterica is divided into 6 subspecies. S. enterica subsp. enterica I is divided into serotypes, for example serotypes enteriditis, typhimurium, typhi and choleraesuis. The majority of 2463 Salmonella serotypes belong to S. enterica subsp. I and associated mainly with warm blooded vertebrates and are responsible for most Salmonella infections in humans and domesticated animals. Other serovars are restricted in their host range causing severe systemic disease in only one host. For example, S. typhi is restricted to infection in humans, S. abortusovis to infection in sheep, S. dublin in cattle, S. abortusequi in horses and S. choleraesuis in pigs. The serotypes (serovars) that most commonly cause Salmonellosis in farm animal species are as follows:

Cattle: S. typhimurium, S. dublin, S. newport

Sheep and goat: S. abortusovis, S. typhimurium, S. dublin, S. anaturn

Pig: S. typhimurium, S. choleraesuis

Horses: S. typhimurium, S. abortusequi, S. anatum, S. newport, S. enteritidis, S. arizona, S. angona, S. heidelbers

The organisms are Gm- and rod shaped of 1-31μX0.5-0.8μ in size. They are motile with peritrichous flagella except one type S. gallinarum pullorum which are always non-motile. They do not form capsules or spores but may possess fimbriae. Salmonellae are aerobic and facultatively anaerobic growing readily on simple media over a range of pH 6-8 and temperature 15-41°C (optimum 37°C). Colonies are large, 2-3 mm in diameter, circular and smooth. On MacConkey and deoxycholate citrate media colonies are colorless due to absence of lactose fermentation. On Wilson and Blair bismuth sulphite medium, jet black colonies with a metallic sheen are formed due to production of H2S. S. paratyphi A and other species do not form H2S, produce green colonies. Selenite F and tetrathionate broth are commonly employed as enrichment media.

Synonyms: Circling disease, Meningoencephalitis, silage disease

It is an infectious fatal disease of wide range of animals and man characterized by encephalitis. It also causes abortion, endometritis and repeat breeding in farm animals. Historically, Listeria was first isolated in 1926 from a natural disease of rabbits characterized by mononuclear leucocytosis and therefore named as Bacillus monocytogenes by Murray and coworker at Cambridge. Later, Pierie who isolated similar bacillus from liver of gerbils in 1927 named it Listerella hepatolytica in honour of surgeon Joseph Lister and finally renamed it Listeria in 1940 due to taxonomic reasons.

Etiology: The disease is caused by L. monocytogenes. The genus Listeria consists of a group of Gm + bacteria of low G+C content closely related to Bacillus, Clostridium, Enterococcus, Streptococcus and Staphylococcus. Out of 6 species reported, only L. monocytogenes and L. ivanovii are considered virulent. Human cases of L. ivanovii infection are rare whereas L. monocytogenes is an important food borne pathogen. L. monocytogenes has been isolated from a variety of food products. Meat, poultry, dairy and vegetable products have been implicated as vehicles of listeriosis. The organism can be isolated from faeces and silage. The organism can be easily destroyed by ordinary disinfectants but may survive in soil and silage for a considerable period of time.

L. monocytogenes is small, coccoid with a tendency to occur in chains. It is aerobic or microaerophilic. It grows on ordinary media within a temperature range of 4-42°C. Growth is improved by addition of glucose, blood or liver extract. Colonies are β haemolytic on blood agar. It ferments glucose and salicin producing acid without gas. Lactose, maltose and sucrose are fermented slowly or not at all and mannitol is not fermented. It is catalase +. It shows tumbling motility when grown at 25°C but at 37°C is non-motile. It is because peritrichous flagella are produced by the bacillus optimally at 20-30°C but scantily or not at all at 37°C.

Leptospirosis is a worldwide zoonosis. According to the occupational groups involved and the nature of the disease presentations, different names have been used, e.g. seven-day fever found commonly in Japan, Cane cutter's disease in Australia, Rice field Leptospirosis in Indonesia and Fort Bragg fever, which appeared as an outbreak in the US. Weil's disease, which is one of the severe forms of this disease, occurs in many countries, including India and other South-East Asian Countries, China, continental Europe and England. Leptospirosis exists in all the five inhabited continents and in a large number of countries. It occurs in tropical, subtropical and temperate zones. Leptospirosis is also an important cause of abortions, stillbirths and reproductive failures in cattle and pigs. Periodic ophthalmia in horse is commonly associated with leptospiral infections. Leptospirosis was first recognized in humans in 1886 by Weil and characterized by icterus. Leptospira have been isolated from a variety of animal species and humans manifesting various clinical syndromes such as mud fever and swine herd disease.

Etiology: The etiologic agent of leptospirosis is Leptospira interrogans. It is a thin spiral organism 0.1mm x 6 -20mm, with tightly set coils, and it is characterized by very active motility, by rotating ("spinning") and bending. Usually one or both ends of this single-cell organism are bent or hooked, but straight forms also occur that rotate and travel more slowly than hooked forms. The cells have pointed ends, either or both of which are usually bent into a distinctive hook. Two axial filaments (periplasmic flagella) with polar insertions are located in the periplasmic space. The structure of the flagellar proteins is complex. Leptospires exhibit two distinct forms of movement, translational and nontranslational. Morphologically, all leptospires are indistinguishable, but the morphology of individual isolates varies with subculture in vitro and can be restored by passage in hamsters. Leptospires have a typical double membrane structure in common with other spirochetes, in which the cytoplasmic membrane and peptidoglycan cell wall are closely associated and are overlain by an outer membrane. Leptospiral lipopolysaccharide has a composition similar to that of other Gram-negative bacteria, but has lower endotoxic activity. Leptospires may be stained using carbol fuchsin counterstain. Leptospires are obligate aerobes with an optimum growth temperature of 28 to 30°C. They produce both catalase and oxidase. They grow in simple media enriched with vitamins (vitamins B₂ and B₁₂ are growth factors), long-chain fatty acids, and ammonium salts. Long-chain fatty acids are utilized as the sole carbon source and are metabolized by b-oxidation. Because of their narrow diameter, the leptospires are best visualized by dark-field illumination or phase contrast microscopy and they do not stain readily with aniline dyes. The free living (L. biflexa) and parasitic leptospires (L. interrogans) are morphologically indistinguishable.

Glanders is a contagious, acute or chronic, usually fatal anthropo zoonotic disease of Equidae caused by Burkholderia mallei and characterized by serial development of ulcerating nodules that are most commonly found in the upper respiratory tract, lungs, and skin. The first recorded description of glanders is from the third century from Aristotle. In 1664, glanders was recognized as a contagious disease and in 1830, it's zoonotic potential was suspected. In the late 1800's, the Mallein test (1891) was developed for diagnosis of glanders. By 1910, the U.S., Canada and Great Britain all implemented glanders controlprograms. B. mallei was eradicated from the United States in 1929.

Etiology: It is caused by Burkholderia mallei. It is a straight or slightly bent Gm - non-spore forming, non-motile rod. The organisms in old culture appear as pleomorphic. The organisms can grow in ordinary media but addition of defribinated horse blood or glycerol accelerate the growth. Colonies have hop like odour and slime consistency. The organisms are readily destroyed by direct sunlight and most of the disinfectants. They can survive for 20 days in water and 6 weeks in contaminated stable. This organism is closely related to the agent of melioidosis, Burkholderia pseudomallei.

Susceptible hosts: The most susceptible hosts are horses, mules and donkeys. Infections can also occur in dogs, cats, goats and camels; cats may be particularly susceptible. Hamsters and guinea pigs can be infected in the laboratory. It is an occupational /professional hazard to human being. Laboratory samples are highly infectious to humans. Infection have been observed in sheep and goats. Guinea pigs, rabbits and field mice may be infected fatally. Cattle and pigs are absolutely resistant.

Geographic Distribution: Glanders is seen in some Middle Eastern countries, the Indian subcontinent, Southeast Asia, parts of China and Mongolia, and Africa. Sporadic cases are also seen in South America. Sporadic cases of glanders were identified between 1985-86 to 1990-91 from the states of Haryana, Himachal Pradesh and Punjab. Since reemergence of glanders in July - August 2006 in and around Pune and Panchgani area of Maharastra, several cases have been reported among equines of different states viz., Andhra Pradesh, Uttar Pradesh, Uttarakhand and Punjab. During the year 2006-07, National Research Centre on Equines, Hissar tested 4395 samples and 97 were detected positive and B. mallei was isolated from 8 of these cases.

Synonyms: Calf scour, white diarrhea, septicaemia of calves

Colibacillosis is one of the important diseases in new born calves, piglets, lambs and foals caused by E. coli and characterized by marked postration, profuse diarrhea and septicaemia.

Etiology: Colibacillosis is associated with pathogenic serotypes of E. coli. Certain serotypes cause diarrhea and others cause septicaemia.

(a)  Enterotoxigenic E. coli: is the most common enteropathogen that causes diarrhea in new born farm animals. It causes bacteria by adhering to, colonizing and producing enterotoxins in the small intestine. They are not invasive. The enterotoxins produced by E. coli are of two types: heat stable (ST) and heat labile (LT).

(b)  Enteropathogenic E. coli: they attach tightly to the epithelial cells of the villus of small intestine. They do not produce toxins and seldom invade the intestine.

(c)  Enterohaemorrhagic E. coli: They are Shiga toxin or verotoxin producing strains of E. coli. They are not an important cause of diarrhea in farm animals but some produce diarrhea in calves. E. coli O157:H7, one of the important enterohaemorrhagic E. coli strains cause a broad range of clinical disease in humans including diarrhea in humans and haemorrhagic colitis and highly fatal haemolytic-uremic syndrome in children. 195

Brucellosis, one of the most ancient diseases, continues to be a problem for humans and animals throughout the world causing enormous economic losses and significant human morbidity in endemic areas. The bacterial pathogen is classified by the CDC as a category B pathogen that has the potential for development as a bioweapon. It is one of the important zoonotic disease and considered as the most common laboratory acquired pathogen with >5 lakh human cases reported annually around the world. Brucellosis is a chronic infection which can result in infertility, delayed heat, interrupted lactation, loss of calves, wool, meat and milk production in animals and undulant fever in humans. Although in most of the counties, brucellosis is a nationally notifiable disease and reportable to the local health authority, it is underreported and official numbers constitute only a fraction of true incidence of the disease. Although the true incidence of human brucellosis is unknown, the estimated burden of the disease varies widely from <0.03 to >160 per 1 lakh population. Although only 17 countries in the world are free from the disease, it has been reported in many countries including India. Bovine brucellosis is endemic in all the states in India and appears to be on the increase in recent time, perhaps due to increased trade and rapid movement of livestock. The preponderance of natural bull service in rural India is perhaps yet another important factor in the maintenance and spread of infection. The Government of India has made it mandatory to regularly screen all the breeding bulls from artificial insemination centres, for brucellosis and to use brucellosis free bulls for semen production.

Etiology: Brucella sp. are facultative intracellular Gram - ve coccobacilli, nonspore forming and non-capsulated. It infects macrophages with principal involvement of liver, spleen and bone marrow. Nine Brucella species are currently recognized, seven of them that affect terrestrial animals are: B. abortus, B. melitensis, B. suis, B. ovis, B. canis, B. neotomae and B. microti and two that affect marine mammals are B. ceti and B. pinnipedialis. The first three species are called classical Brucella and within these species seven biovars are recognized for B. abortus, three for B. melitensis and five for B. suis. The remaining species have not been differentiated into biovars.

Synonyms: Pearl's disease, scrofula

It is a chronic insidious contagious disease of man and animals caused by tubercle bacilli characterized by development of tubercles in lung tissue, lymph nodes or other organs resulting in caseation and calcification. The tubercles are frequently located in lungs and lymph nodes. But they may be formed in the liver, spleen, intestine, peritoneum, meninges and long bones. It is a zoonotic disease. Bovine tuberculosis, caused by Mycobacterium bovis (M. bovis) is considered as the serious epizootics of animals and humans. Bovine species are natural hosts to the disease, but a wide spectrum of domestic and wild animals, as well as man, can be infected. Animals reported as having been infected with M. bovis include North American bison (Bison bison), buffaloes (Syncerus caffer), elk (Cervus elaphus), domestic and wild pigs domestic (Sus scrofa), goats (Capra hircus), camels (Camelus bactrianus), dogs (Canis familiaris), cats (Fells catus), sheep (Ovis aries), possums (Trichosurus vulpecula), badgers (Meles meles), mink (Lutreola vison), ferrets (Putorius furo) and non-human primates. All species are not equally susceptible, and are often grouped into spill-over (end) hosts and maintenance hosts. Cattle and other bovine species are considered the primary and most well-known reservoirs or maintenance hosts. In countries where maintenance hosts are present endemically in the wild, infection from these populations to domestic cattle or other farm animals is difficult to avoid. In Africa, bovine TB primarily affects cattle; however, infection in other farm and domestic animals, such as sheep, goats, pigs, dogs and cats, is not uncommon. Wild ruminants and carnivores are also affected and are the natural reservoirs of the infectious agent in the wild. Man is also susceptible to the disease, the highest risk groups being individuals with concomitant HIV/AIDS infection. In Africa, human TB is widely known to be caused by M. tuberculosis; however, an unknown proportion of cases are due to M. bovis. This infection in humans is underreported as a result of the diagnostic limitations of many laboratories in distinguishing M. bovis from M. tuberculosis. TB is a neglected public health problem and accounts for about 25% of all avoidable adult deaths in developing countries. It is of socio-economic significance, as it can affect international trade in animals and animal products. Many factors account for the failure of developing countries to control and eradicate bovine TB, many of them politico-economic. Added to the high costs of a sustainable testing programme are problems of social unrest due to political instability and ethnic wars, resulting in the displacement of large numbers of human and animal populations; lack of veterinary expertise and communication networks; insufficient collaboration with bordering countries and hence a lack of quarantine; and smuggling of live animals across state boundaries. Scarce human and financial resources are often absorbed by action against the high incidence of other acute and fatal diseases, such as contagious bovine pleuropneumonia, foot and mouth disease, African and classical swine fever and parasitic diseases. The primary sources of infection for humans are consumption of unpasteurised milk and close association between humans and animals. Rural inhabitants and some urban dwellers in Africa still consume unpasteurised and soured milk potentially infected with M. bovis. Milk borne infection is the main cause of non-pulmonary TB in areas where bovine TB is common and uncontrolled.

Synonyms: Splenic fever, wool sorter's disease, Tarka

It is an infectious disease of livestock and worldwide in distribution. This is a zoonotic disease. It is also known as splenic fever because of enlargement of the spleen (splenomegaly).

Etiology: It is caused by a rod shaped bacteria of 4-8 µm X 1-1.2 µm known as Bacillus anthracis. It is non-motile, capsulated, aerobic, spore bearing and Gm+ in nature. The organisms remain in chains. It was the first pathogenic bacterium to be observed under the microscope, the first communicable disease to be transmitted by inoculation of infected blood, the first bacillus to be isolated in pure culture and shown to possess spores and the first bacterium used for preparation of an attenuated vaccine.

The capsule is polypeptide in nature being composed of a polymer of d(-) glutamic acid. Capsules are not formed under ordinary conditions of culture but only if the media contain added bicarbonate or are incubated under 10-25% CO₂. Capsules are formed in the body of an infected animal.

Spores are formed in culture or in the soil, but never in the animal body during life. Spores are formed only in the presence of O₂. Spores are central, elliptical or oval in shape. The spores are very resistant to physical and chemical agents. They have been isolated from naturally infected soil for as long as 60 years. They resist dry heat at 140°C for 1-3 h and boiling for 10 min.

Anthrax bacilli is Gm + and non-acid fast. When blood films containing anthrax bacilli are stained with polychrome methylene blue for a few seconds and examined under the microscope, an amorphous purplish material (capsule) is noticed around the bacilli called M'Fadyean's reaction. On agar places, irregularly round colonies are formed 2-3 mm in diameter raised, dull opaque, grayish white with a frosted glass appearance. Under the low power microscope, the edge of the colony is composed of long, interlacing chain of bacilli, resembling locks of matted hair. This is called "Medusa head appearance." Virulent capsulated strains form rough colonies while avirulent or attenuated strains form smooth colonies. On gelatin stab culture, a characteristic 'inverted fir tree' appearance is seen with slow liquefaction commencing from the top.

Crimean Congo hemorrhagic fever (CCHF) was first reported in the 12^th century as a hemorrhagic syndrome in present day Tajikistan. However, in the modern era, the first outbreak of the CCHF was reported in 1944-1945 in the Crimea region with more than 200 cases and the disease was called Crimean Hemorrhagic Fever. Ten years later in 1956, the virus was isolated from a febrile patient in Belgian Congo and this isolate was noted to have the same antigenic structure with the Crimean strains. For this reason, the virus was called Crimean Congo Hemorrhagic Fever. Nowadays, outbreaks of CCHF have been documented in Africa, the Middle East, Eastern Europe, and Western Asia including India. CCHF is a severe hemorrhagic fever with a case fatality rate of up to 50%.

Etiology: It is a tick-borne viral disease belonging to the family Bunyaviridae, genus Nairovirus. Like other Nairoviruses, CCHF virus is an enveloped single stranded negative-sense RNA virus and its tripartite genome consists of a small (S), a medium (M) and large (L) segment which encode for the nucleocapsid protein (NP), the envelope glycoproteins G1 and G2 and an RNA-dependent polymerase, respectively. The virus is transmitted to humans through the bite of infected ticks or by direct contact with viremic animals or humans. Infected humans can spread the disease via close contacts which may result in community outbreaks and nosocomial infections. It is an important human pathogen and could be used as a bioterrorism agent.

Pathogenesis: The pathogenesis of CCHF is not well understood. A common pathogenic feature of hemorrhagic fever viruses is their ability to disable the host immune response by attacking and manipulating the cells that initiate the antiviral response. This damage is characterized by marked replication of the virus together with dysregulation of the vascular system and lymphoid organs. Endothelial damage contributes to hemostatic failure by stimulating platelet aggregation and degranulation, with consequent activation of the intrinsic coagulation cascade. DIC is noted as an early and prominent feature of the disease process. In another study, the levels of interleukin IL-1, IL-6, and TNF-alpha were higher among patients who subsequently died as compared to survivors. The DIC score was higher among fatal cases, correlating positively with IL-6 and TNF alpha levels, and negatively with IL-10 levels. These findings demonstrate that proinflammatory cytokines play a major role in pathogenesis and mortality of patients with CCHF.

Marburg virus (MV) disease was named after the West German town where the largest outbreaks of human infection was reported. It is also known as Vervet monkey or green monkey disease as monkey species introduced the disease in Europe. Marburg disease virus was reported in 1967 in Frankfurt-on-Main and Marburg, West Germany and Belgrade, Serbia in vaccine factory workers who came in contact with blood, organs or cell cultures of African green monkeys. Ebola and Marburg hemorrhagic fevers are severe zoonotic diseases seen not only in humans but also in non-human primates. Most species of Ebolavirus and the only known species of Marburg virus occur in Africa. Primates are infected sporadically from an unknown source probably bats. Humans seem to become infected directly from bats in caves, as well as when they, come in contact with tissues from infected apes and other species. Once the virus has entered the population, it can spread from person to person. Some epidemics affect hundreds of people. Although the mortality rate varies, 90% case fatalities have been reported in the most pathogenic viruses. No vaccine is available and the only treatment is supportive. Epizootics in gorillas and chimpanzees are equally serious, and appear to threaten the survival of these species in the wild. Other wild mammals including duikers also seem to be killed during outbreaks. One species of Ebolavirus, Reston Ebolavirus, occurs in the Philippines. Until 2008, this virus was known only as an infection of nonhuman primates. It does not appear to be a human pathogen; although some people in contact with this virus have seroconverted, they remained asymptomatic. In December 2008, Reston ebolavirus was discovered in pigs during an unusually severe outbreak of porcine reproductive and respiratory syndrome (PRRS) in the Philippines.

Etiology: Ebola and Marburg hemorrhagic fever are caused by members of the genera Ebolavirus and Marburgvirus, respectively. These viruses are the only members of the family Filoviridae. The genus Ebolavirus contains four recognized species: Zaire ebolavirus (formerly Zaire Ebola virus), Sudan ebolavirus (formerly Sudan Ebola virus), Ivory Coast ebolavirus (formerly Cote d'Ivoire Ebola virus) and Reston ebolavirus (formerly Reston Ebola virus). At least 13 strains of these viruses have been identified. A fifth species, tentatively named Bundibugyo ebolavirus, was isolated from a recent outbreak in Uganda. Marburg virus contains a single species, Lake Victoria Marburgvirus (formerly Marburg virus). Six strains of Lake Victoria Marburgvirus had been recognized as of 1990; at least nine genetically distinct strains were identified from a more recent outbreak in the Democratic Republic of the Congo. Marburg virus contains ssRNA as genome. The virion is highly pleomorphic and measures 80 nm in diameter and 700-1000 nm in length. Filoviruses can be destroyed by autoclaving. Treatment with sodium hypochlorite (1:100 dilution of household bleach) or standard hospital disinfectants can also be used. Ebolaviruses are reported to be susceptible to 2% sodium hypochlorite, 2% glutaraldehyde, 5% peracetic acid and 1% formalin. These viruses can also be inactivated by ultraviolet light, gamma irradiation, 0.3% betapropiolactone for 30 minutes at 37°C (98.6°F), or heating to 60°C (140°F) for 1 hour. Marburgvirus is susceptible to 1% sodium hypochlorite, 2% glutaraldehyde or formaldehyde, ultraviolet light and heat.

Hantaviruses have been responsible for a variety of human illnesses particularly haemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). There are currently 47 recognized sero/genotypes of hantaviruses with considerable geographic diversity. Each hantavirus type appears to be specific to a different rodent host. The different hantavirus types are associated with different types of disease both in terms of target organs and disease severity. HFRS is primarily a disease of the Old World while HPS is a disease of New World. Although the disease may have first been recognized as early as 1000 years ago in China, it affected >3000 United Nations Soldiers during Korean war (1950-1953). Now it is reported that hantavirus affect as many as 2 lakhs people each year in Asia and Europe. The agent of this virus remained unknown until 1978 when Lee and his associates isolated and named Hantaan virus, after a river in South Korea. Other viruses antigenically related to Hantaan virus were characterized and placed under the genus Hantavirus and family Bunyaviridae.

Over the past few decades, the sharp increase of incidences of hantavirus disease in humans throughout the world has been reported. There are 47 recognized hantaviruses with considerable geographic diversity. But the number of hantavirus virus types recognized continues to grow. Hantaviruses cause persistent infections in rodent reservoirs which directly impact transmission of these zoonotic agents between rodents and from rodents to humans. Environmental, 127 demographic and physiological factors likely interact to mediate responses to hantaviruses in natural rodent populations. Although not much work has been carried out, comparisons of human and rodent immune responses to hantaviruses may provide insights into why hantaviruses often are fatal for humans but cause only persistent infections in rodents.

Nipah virus infection is an emerging zoonotic disease first described in 1999 and the virus is under the genus Henipavirus and family Paramyxoviridae. The disease is similar to another emerging zoonotic disease caused by Hendra virus and can spread from its wildlife reservoir to pigs and humans where it causes an often fatal disease. It is a notifiable disease in most countries and to be handled under highest biological security level 4 (BSL-4). In Malayasia an outbreak of viral encephalitis occurred over a 35 week period from September 29, 1998 to 31^st May, 1999 among pig farmers creating considerable anxiety and fear. Of the 265 cases reported to the Ministry of Health in Malaysia, 105 were fatal and the case fatality rate was 39.6%. The outbreak also spread to neighbouring Singapore where 11 workers of an abattoir developed the disease with one fatality. 93% of the reported cases involved those directly in the pig farming industries namely pig farm workers, pig farm proprietors, housewives and family members assisting in the farms. The majority of the cases occurred in those aged 20 and above (92.4%) and actively engaged in pig industry followed by the age group 10-19 years (6.4%). About 82.6% of the cases are male.

Etiology: Henipavirus is a genus of the family Paramyxoviridae and order Mononegavirales containing two members, Hendravirus and Nipah virus. The henipaviruses are naturally harboured by Pteropid fruit bats (flying foxes) and are characterized by a large genome (18.2 Kb), wide host range and their recent emergence as zoonotic pathogens capable of causing illness and death in domestic animals and humans.

The viruses are pleomorphic ranging in size from 40-600 nm in diameter. They possess a lipid membrane overlying a shell of viral matrix protein. At the core is a single helical strand of genomic RNA tightly bound to N (nucleocapsid) protein and associated with the L (large) and P (phospoprotein) proteins which provides the RNA polymerase activity. F (fusion) protein trimers and G (attachment) protein tetramers are embedded within the lipid membrane. The genome of the Nipah virus consists of a non-segmented, single stranded negative sense RNA. In common with other members of the Paramyxovirinae subfamily, the number of nucleotides in the Henipavirus genome is a multiple of six, known as the 'rule of six'. The Nipah virus has been classified by the CDC as a Category C agent.

Hendra, a disease of horse has been recognized in Australia since 1994-95 with zoonotic importance. It is caused by a virus under the genus Megamyxovirus and subfamily Paramyxovirinae and family Paramyxoviridae. This virus is also endemic in certain species of bat. Another zoonotic bat virus called Nipah virus has been placed under the same genus and family. It is transmitted between the horses through contact. Infected horses can develop a severe and fatal respiratory disease characterized by dyspnoea, vascular endothelial damage, pulmonary oedema and neurological signs. Experimental infection of cats and guinea pigs showed fatal respiratory disease. The transmission of virus from horse to horse and horse to man is through close contact. One person died of the disease due to respiratory failure and another one due to delayed onset of encephalitis. A number of diagnostic methods are available to provide prompt, sensitive and accurate diagnosis of the disease.

History: In 1994-95, a new viral zoonotic disease was identified in Queensland, Australia resulting in death of 2 human and 15 horses in two separate incidents. Again, in 1999 another horse died at the same place. The term 'Hendra' has been derived from the name of a place, suburb of Brisbane where first outbreak took place. In September 1994, a total of 15 horses died due to hyperacute respiratory disease. The trainer of the horse also died. In 1995, a farmer died of meningoencephalitis after having contact with a Hendra positive horse. In the 1999, a mare died of Hendra virus infections.

Etiology: The Hendra virus is under the new genus Megamyxovirus and family Paramyxoviridae. The Hendra virus was isolated in Vero cells from lung specimens and produced CPE within 3 days. The virus can grow in MDCK, BHK, RK13, LLC-MK2 and MRC5 cells. It also grows in cells derived from birds, reptiles, amphibians, fish and in embryonated chicken eggs. The virus does not have haemagglutinin or neuraminidase activity. The virus is pleomorphic in shape, 38-600 nm in diameter and enveloped with two glycosylated transmembrane proteins of different lengths (15 and 18 nm). It differs from respirovirus and rubulavirus in not using sialic acid containing receptors. The virions are labile and infectivity is destroyed by heat, lipid solvents, non-ionic detergents, formaldehyde and oxidizing agents. Virions contain one molecule of negative sense ssRNA about 15 Kb long which codes 8 proteins. The Hendra virus is the largest of all known viruses under Paramyxoviridae. The genetic studies showed that Hendra virus is more similar to Morbillivirus or intermediate between Morbillivirus and Respirovirus. The amino acid homology between Hendravirus and Morbillivirus varies from 17-21% (P protein) to 40-42% (M protein) compared to 6-10% and 8% respectively for other members of Paramyxoviridae. A new Hendra like virus has been identified as a cause of respiratory and neurological disease in pigs and humans in Malaysia, called Nipah virus, after a village where the first human case occurred. (The amino acid homology of N protein between Hendra and Nipah is 92%, whereas in case of P&V it is 80-85%). Like, Hendra virus, the Nipah virus is thought to have emerged from a fruit bat (Pteropus hypomelanus).

This is an acute viral encephalitis having public health importance. It is under the genus Flavivirus and family Flaviviridae. The genus Flavivirus comprises of group of arbovirus though a few members of the genus have no known vector. The genus contains over 70 viruses of which 40 are mosquito borne, 16 are tick borne and 18 have no known vector. The type species of the genus is yellow fever virus. Although all flaviviruses are serologically relate, they can also be grouped serologically into distinct groups: dengue serological group, the JE serological group and a less serologically cohesive yellow fever virus group. The disease has been recognized in Japan since 1871 and was named Japanese B encephalitis to distinguish it from 'encephalitis A' (encephalitis lethargica, Von economo's disease) which was then prevalent. The virus was first isolated in Japan during an epidemic in 1935.

Etiology: JE virus is under the genus Flavivirus and family Flaviviridae. The genome is about 11 kb which encodes 3 structural proteins (C, capsid protein, PrM the membrane precursor protein that is cleaved proteolytically by a cellular protease to form the M protein in mature virions, and E, envelope protein) and 7 non-structural (NS) protein (NS1, NS2a, NS2b, NS3, NS4a, NS4b, NS5). The Eglycoprotein is the most immunologically important protein. The Japanese encephalitis serological group of flaviviruses comprises eight virus species and two subtype viruses with a geographic range encompassing all continents except Antarctica. The major virus species and their geographic range are as follows: the Japanese encephalitis virus ( JEV) in eastern, southern and southeastern Asia, Papua New Guinea and the Torres Strait of northern Australia; the West Nile virus (WNV) in Africa, southern and central Europe, India, the Middle East and North America and as Kunjin virus ( a subtype of WNV) in Australia and Papua New Guinea; the Murray Valley encephalitis virus (MVEV) in Australia, Papua New Guinea and the western Indonesian archipelago and the St. Louis encephalitis virus (SLEV) in North and South America. The other minor members of the group are Usutu (USUV), Koutango and Yaounde viruses in Africa; Cacipacore virus in South America and Alfuy, a subtype of MVEV, in Australia.