Introduction

Foot and mouth disease (FMD) is highly contagious disease of the cloven-hoofed domestic and wild animals leading to significant economic losses to dairy industry and restriction in international trade of animals and animal products (OIE, 2010; Verma et al., 2012; Chakraborty et al., 2014). The disease is caused by Aphthovirus of Picornaviridae family and characterized by high fever, formation of vesicles in the mouth, teats and feet, profuse salivation (Thomson, 1994; Chakraborty et al., 2014) with almost 100% morbidity (OIE, 2010) and mortality may reach upto 50% in calves, when the virus replicates in heart muscles of claves (Gulbahar et al., 2007; Verma et al., 2008). The virus has seven serotypes (O, A, C, Asia-1, SAT-1, SAT-2 and SAT-3) but in India only four serotypes (O, A, C and Asia-1) are prevalent (Verma et al., 2012). FMD is endemic in India and is often underreported either due to its endemicity and the fact that it is not associated with high mortalities in adult susceptible animals, as such it is not considered as an important livestock disease among animal owners or farmers (Verma et al., 2012). The aim of the present study is to investigate the presence of FMD virus (FMDV) in reported FMD-suspected cases and the secondary bacteria known to accompany FMD and to find the reason for high mortality rate.

Materials and Methods

Study Area, Animals and their Management

The FMD outbreak in cattle and buffaloes was suspected in March, 2015 in the Shekhupur Raura village of district Bulandsahar located in Uttar Pradesh, India (Fig. 1). The livestock population of the affected village was around 5000 including cattle, buffaloes, goats and pigs at the time of incident. The animals were stall fed and had access to water twice/thrice a day.

Fig. 1: Uttar Pradesh Map showing the location of Bulandsahar district

History, Clinical Examination and Data Collection

Animals were examined by the experts from Uttar Pradesh Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishwavidyalaya Ewum Go-Anusandhan Sansthan (DUVASU), Mathura, India, along with Veterinary Officers of Animal Husbandry Department, Uttar Pradesh. Animals were showing clinical signs such as pyrexia (high rectal temperature more than 105⁰F), vesicles on gums, dental pads, tongue, foot and udder, increased salivation, anorexia and reluctant to move.

Sample Collection

The specimens (vesicular epithelium from tongue and gums) were collected in 50% phosphate buffer saline-glycerol (PBS-glycerol) (Kitching and Donaldson, 1987), while blood samples were collected in vacutainers from affected animal and brought to laboratory in cold chain.

Laboratory Examination

Vesicular epitheliums were sent to Central Laboratory, All India Co-ordinated Research Project on FMD, Indian Veterinary Research Institute, Mukteswar, Nainital, India for confirmation of FMD serotypes. The sera samples were screened for the presence of antibodies against foot-and-mouth disease virus using DIVA-ELISA kit provided by project directorate on foot and mouth disease, Mukteswar, Nainital as per the manufacturer’s protocol.

Result and Discussion

Out of 87 animals (cattle and buffaloes) that were physically examined in the affected village, 16 (18.4%) animals showed clinical signs and lesions suggestive of FMD. The principal clinical signs were fever, salivation and lameness. Mouth lesions include erosions and ulcers on tongue, dental pad etc. (Fig. 2 and 3).

Fig. 2: Ruptured Vesicle on dental pad of cattle	Fig. 3: Ruptured Vesicle on lower jaw of cattle

Foot lesions comprised of erosions on the interdigital spaces and the coronary bands (Alexandersen et al., 2003; Teifke et al., 2012; Yoon et al., 2012; Chakraborty et al., 2014). Some of the affected animals especially cattle showed foot lesions and, in most cases, healing mouth lesions where also observed. Few animals were died during the outbreak in the affected area. Results of DIVA analysis also showed the presence of antibodies against FMDV using DIVA-ELISA. For effective control of FMD, outbreaks should be detected at an early stage and persistent infections should be recognised to prevent further transmission of the virus (Longjam et al., 2011). The presence of clinical signs coupled with confirmation of presence of antibodies against FMDV from animals of the affected area confirmed that the majority of the animals in this area had been infected by FMDV. Due to the foot lesions, which are characteristic of FMD, some animals were observed as having difficulties in moving; this was previously reported by Hunter, 1997.

In the present investigation, heavy mortality was reported in the animals, who were not vaccinated against FMD, while the mortality was very low in vaccinated animals. Incubation period for FMD remain largely unknown for field outbreaks or around 2-13 days (Coetzer et al.,1994) as against less than 24 hrs after experimental inoculation (Timoney et al., 1988). As the transmission of disease is rapid mainly through aerosol (Alexandersen et al., 2003; Chakraborty et al., 2014) and/or contaminated feed and water, the isolation of affected animals and vaccination of apparently healthy animals (Orsel and Bouma, 2009; Amal et al., 2011) prevents the spread of the disease to further area by removing the chain reaction from one animal to another.

During the investigation of the outbreak in the Bulandsahar district, a discussion with local people in the area revealed that round the year there is purchase of high yielding animals from neighboring districts as well as states, which mingles with local herds of cattle and buffaloes (Sharma et al., 1991). Since, Bulandsahar district of Uttar Pradesh is one of the largest milk producing districts in the state having large number of dairies, where animals are frequently replaced by input from neighboring states viz., Punjab, Haryana and Rajasthan resulting in the frequent turnover in their population. Furthermore, vaccinations where not conducted in some of the animals within the affected area. Villagers also revealed that cattle traders usually pass by the villages on their way home from these markets with their animals. During this time, the traders’ animals interact with the local animals. During the marriage, cattle and buffaloes are usually used as gift with bride. Intermarriages are also common on the borders and cattle are usually used for payment of the bride. This also entails movement of animals from one family to another. In addition, pockets of farmers deliberately do not vaccinate their animals.

Conclusion

This study has detected the presence of antibodies to FMDV in the serum samples collected from the affected animals. Furthermore, clinical signs and laboratory tests suggested that it was outbreak of FMD in Bulandsahar district. This study could not conclude the sources of this outbreak, although information on the ground indicated that this could be from movement and interaction of animals from neighboring districts or states. It is also recommended that animal traders should be sensitised on the potential risk of transmission of FMDV among animals. Restriction of animal movement along with identification and the monitoring of animal movements are necessary to identify the cross-border movements and market chain interactions of ruminants must be enforced to minimise further trans-boundary transmission of the disease. This could be done by setting up more veterinary camps and increasing the number of veterinary staff in FMD high-risk areas.

Acknowledgement

Authors are highly thankful to Dean, College of Veterinary Science and Animal Husbandry, and Hon’ble Vice Chancellor, Uttar Pradesh Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishwavidyalay Evum Go-Anusandhan Sansthan (DUVASU), Mathura, India; for providing all the necessary support and facilities for conducting this investigation. Authors wish to thank Chief Veterinary Officer, Bulandsahar and other Veterinary Officers of the district for providing help in disease investigation. Authors are also thankful to Project Director, All India Co-ordinated Research Project on Foot-and-Mouth disease, for providing the diagnostic kits and necessary facilities in conducting this study.

References

1. Alexandersen, S., Zhang, Z., Donaldson, A. I. and Garland, A. J. M. (2003). Review: The Pathogenesis and diagnosis of Foot-and-Mouth Disease. Journal of Comparative Pathology. 129: 1-36.
2. Amal M.A. Raof, Iman Y. Haleem, Nawal M. Aly, M.M. Garhy and Gehan A. Hosny, 2011. Epidemiological Diagnosis of Foot and Mouth Disease among Cattle in Sharkia and Kafr El Sheikh Governorates. International Journal of Virology, 7: 191-197.
3. Bauer, A. W., Kirby, W. M. M., Sherris, J. C. and Turck, M. (1966). Antibiotic sensitivity testing by a standardized single disk method. Am. J. Clin. Path., 45:493-496.
4. Chakraborty, S., Kumar, N., Dhama, K., Verma, A.K., Tiwari, R., Kumar, A., Kapoor, S. and Singh, S.V. (2014). Foot–and–Mouth disease, an economically important disease of animals. Adv. Anim. Vet. Sci. 2(2S): 1-18.
5. Clinical and Laboratory Standards Institute (CLSI) (2006). Performance Standards for Antimicrobial Disk Susceptibility Tests. Approved standard M2-A8.
6. Coetzer, J.A.W., Thomson, G.R. and Tustin R.C. (1994). Infectious Diseases of Livestock with special reference to Southern Africa. Oxford University Press, Cape Town, South Africa. 2: 825-852.
7. Cruickshank, R., Duguid, B.P., Marmion, B.P. and Swain, R.H.A. (1975). Medical Microbiology. 12th Edn., Churchill, Lavingstone, Edinburgh, UK pp: 356
8. Gulbahar M Y, Davis W C, Guvenc T, Yarim M, Parlak U and Kabak Y B. 2007. Myocarditis Associated with Foot-and-Mouth Disease Virus Type O in Lambs. Veterinary Pathology 44: 589-599.
9. Hunter, P., 1997, ‘Vaccination as a means of control of foot and mouth disease in Sub-Saharan Africa’, Vaccine 16(2/3), 261-264.
10. Kitching, R.P. & Donaldson A.I., 1987, ‘Collection and transportation of specimens for vesicular virus investigation’ Revise Science Techniques Office International Epizotics 6, 263-272.
11. Longjam, N., Deb, R., Sarmah, A.K., Tayo, T., Awachat, V.B. & Saxena, V.K., 2011, ‘A Brief Review on Diagnosis of Foot-and-Mouth Disease of Livestock: Conventional to Molecular Tools’, Veterinary Medicine International 2011, 905768.
12. OIE. (2010). OIE terrestrial manual. Chapter 2.1.5. Foot and Mouth Disease. Office International des Epizooties, Paris, France.
13. Orsel, K. and Bouma, A. (2009). The effect of foot-and-mouth disease (FMD) vaccination on virus transmission and the significance for the field. Can Vet J. 50(10): 1059–1063.
14. Sharma, S. K., Singh, G. R. and Pathak, R.C. (1991). Seasonal contours of foot and mouth disease in India. Indian Journal of Animal Sciences, 61(12): 1259-61.
15. Thomson GR (1994). Foot and Mouth Disease. In: Infectious diseases of livestock with special reference to Southern Africa, edited by JAW Coetzer, GR Thomson (eds.). Cape Town, Oxford University Press. pp. 825-992.
16. Teifke JP, Breithaupt A and Haas B (2012). Foot-and-mouth disease and its differential diagnoses. Tierarztl. Prax. Ausg. G Grosstiere Nutztiere. 40(4): 225-237.
17. Timoney, J. F., Gillespie, J. H., Scott F. W. and Barlough, J. E. (1988). Hagan and Bruner’s Microbiology and Infectious Diseases of Domestic Animals Eighth Edition Cornell University Press, Itheca and London. 8th edition.
18. Verma, A.K., Kumar, A., Mahima and Sahzad (2012). Epidemiology and diagnosis of foot and mouth disease: a review. Indian Journal of Animal Sciences, 82 (6): 543-551.
19. Verma, A.K., Pal, B.C., Singh, C.P., Jain, U., Yadav, S.K. and Mahima. (2008). Studies of the outbreaks of foot-and-mouth disease in Uttar Pradesh, India, between 2000 and 2006. Asian Journal of Epidemiology, 1(2):40-46.
20. Verma, A.K., Kumar, A., Neha, Rahal, A. and Bist, B. (2014). Multidrug resistant Pseudomonas aeruginosa: a secondary invader and cause of mortality in Foot-and-Mouth Disease outbreak. Global Journal of Medical Research: G 14(3): 7-10.
21. Yoon H, Yoon SS, Wee SH, Kim YJ and Kim B (2012). Clinical manifestations of foot-and-mouth disease during the 2010/2011 epidemic in the Republic of Korea. Transbound. Emerg. Dis. 59(6): 517-525.