Foot-and-mouth disease virus transmission dynamics and persistence in a herd of vaccinated dairy cattle in India

Authors: HAYDER, SHIVDEEP - University Of Minnesota; VANDERWAAL, KIMBERLY - University Of Minnesota; RANJAN, RAJEEV - Indian Council Of Agricultural Research-Directorate Of Foot And Mouth Disease; BISWAL, JITENDRA - Indian Council Of Agricultural Research-Directorate Of Foot And Mouth Disease; SUBRAMANIAM, SARAVANAN - Indian Council Of Agricultural Research-Directorate Of Foot And Mouth Disease; MOHAPATRA, JITTENDRA - Indian Council Of Agricultural Research-Directorate Of Foot And Mouth Disease; SHARMA, GAURAV - Indian Council Of Agricultural Research-Directorate Of Foot And Mouth Disease; ROUT, MANORANJAN - Indian Council Of Agricultural Research-Directorate Of Foot And Mouth Disease; DASH, BANA BIHARI - Indian Council Of Agricultural Research-Directorate Of Foot And Mouth Disease; DAS, BISWAJIT - Indian Council Of Agricultural Research-Directorate Of Foot And Mouth Disease; PRUSTY, BIKASH RANJAN - Indian Council Of Agricultural Research-Directorate Of Foot And Mouth Disease; SHARMA, AJAY - Indian Veterinary Research Institute; STENFELDT, CAROLINA - University Of Minnesota; PEREZ, ANDRES - University Of Minnesota; DELGADO, AMY - Animal And Plant Health Inspection Service (APHIS); SHARMA, M - Ib Group-Abis Dairy; Rodriguez, Luis; Arzt, Jonathan

Submitted to: Transboundary and Emerging Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2017
Publication Date: 12/5/2017
Citation: Hayder, S.S., VanderWaal, K., Ranjan, R., Biswal, J.K., Subramaniam, S., Mohapatra, J.K., Sharma, G.K., Rout, M., Dash, B., Das, B., Prusty, B., Sharma, A.K., Stenfeldt, C., Perez, A., Rodriguez, L.L., Arzt, J. 2017. Foot-and-mouth disease virus transmission dynamics and persistence in a herd of vaccinated dairy cattle in India. Transboundary and Emerging Diseases. 65(2):e404-e415. https://doi.org/10.1111/tbed.12774.
DOI: https://doi.org/10.1111/tbed.12774

Interpretive Summary: Foot-and-mouth disease (FMD) is the most important infectious disease limiting global trade in livestock and animal-derived products. Transmission of FMD between different herds of cattle has been well studied. However, there have been fewer studies of how the disease spreads within a single herd under natural conditions. The aim of this study was to evaluate and model how the disease spread during an outbreak of FMD on a dairy farm in India in 2013. Out of 1836 animals on the farm, 222 developed clinical (visible) signs of FMD during the 39 day period of the outbreak. The calculations showed that non-pregnant cattle were more likely to get sick compared to pregnant cattle. The investigation also showed that 10 months after the outbreak, four out of 36 animals, were still persistently infected with FMD-virus (FMDV). At 12 months after the outbreak, 83% of animals that had been clinically sick had antibodies against FMDV. These findings are important for animal health managers and regulatory agencies to improve preparedness for FMD outbreaks in the United States.

Technical Abstract: Foot-and-mouth disease (FMD) is an important transboundary disease with substantial economic impacts. Although between-herd transmission of the disease has been well studied, studies focusing on within-herd transmission using farm-level outbreak data are rare. The aim of this study was to estimate parameters associated with within-herd transmission, host physiological factors, and FMDV persistence using data collected from an outbreak that occurred at a large, organized dairy farm in India. Out of 1836 regularly vaccinated, adult dairy cattle, 222 had clinical signs of FMD over a 39 day period. Assuming homogenous mixing, a frequency dependent compartmental model of disease transmission was built. The transmission coefficient and basic reproductive number were estimated to be between 16.2 - 18.4 and 67 - 88, respectively. Non-pregnant animals were more likely to manifest clinical signs of FMD as compared to pregnant cattle. Based on oropharyngeal fluid (probang) sampling and FMDV-specific RT-PCR, four out of 36 longitudinally sampled animals (14%) were persistently infected carriers 10.5 months post-outbreak. There was no statistical difference between subclinical and clinically infected animals in the duration of carrier state. However, prevalence of NSP-ELISA antibodies differed significantly between subclinical and clinically infected animals 12 months.