|RANJAN, RAJEEV - Indian Council Of Agricultural Research (ICAR)|
|BISWAL, JITENDRA - Indian Council Of Agricultural Research (ICAR)|
|SUBRAMANIAM, SARAVANAN - Indian Council Of Agricultural Research (ICAR)|
|SINGH, KARAM - Indian Veterinary Research Institute|
|STENFELD, CAROLINA - Oak Ridge Institute For Science And Education (ORISE)|
|PATTNAIK, BRAMHADEV - Indian Council Of Agricultural Research (ICAR)|
Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2016
Publication Date: 12/15/2016
Citation: Ranjan, R., Biswal, J.K., Subramaniam, S., Singh, K.P., Stenfeld, C., Rodriguez, L.L., Pattnaik, B., Arzt, J. 2016. Foot-and-mouth disease virus-associated abortion and vertical transmission following acute infection in cattle under natural conditions. PLoS One. 11(12):e0167163.
Interpretive Summary: Foot-and-mouth disease (FMD) is a highly contagious viral disease of livestock and wild cloven-hoofed animals which exists throughout much of Africa, Asia, and South America. It has been long-suspected that the virus that causes FMD may induce abortions in affected pregnant animals. However, it has never been proven under natural conditions. In 2013-14, during recent FMD outbreaks in India, spontaneous abortions were reported in cows at 2 dairy farms. The current study documents that aborted fetuses contained FMDV, and that the cows were infected before abortion. Thus, this is the strongest evidence ever collected that FMDV may cause abortions in cows.
Technical Abstract: Foot-and-mouth disease (FMD) is a highly contagious and economically important viral disease of cloven-hoofed animals, including domestic as well as more than 70 wild host species. During recent FMD outbreaks in India, spontaneous abortions were reported amongst FMD-affected and asymptomatic cows. The current study was an opportunistic investigation of these naturally occurring bovine abortions to assess potential vertical transmission of FMDV from infected cows to fetuses. For this purpose, fetal tissue samples: heart, liver, kidney, spleen, palatine tonsil, umbilical cord, soft palate, tongue, lungs, and submandibular lymph node, were collected and screened by various detection methods, including viral genome detection (GD), virus isolation (VI), and immunomicroscopy. Out of eight cases that were available for examination, gross pathological changes were observed in 3 abortuses. Pathological findings included blood-tinged peritoneal and pleural fluid and myocarditis. FMDV serotype O viral genome was recovered from 7 of 8 cases. Infectious FMDV serotype O was rescued by chemical transfection of the total RNA extracted from three soft palate samples and was sequenced to confirm 100% identity of the VP1 (capsid) coding region with isolates collected from infected cattle during the acute phase of infection. Hearts of infected calves had mild to moderate degeneration and necrosis of the myocardium with moderate infiltration by mixed inflammatory cells. Localization of FMDV antigen was demonstrated in lungs and soft palate by immunomicroscopy. Based upon these findings, it may be concluded that FMDV-associated abortion occurred among the infected pregnant cows included within this study and FMDV was subsequently transmitted vertically to fetuses.