Clinico-molecular diagnosis and phylogenetic investigation of foot-and-mouth disease in small ruminant population of India

Small ruminants (sheep and goats) are susceptible to foot-and-mouth disease (FMD), while studies with due emphasis on their role in the disease epidemiology have been meagre. The present study summarizes the results of clinico-molecular investigation of FMD in sheep and goats across several states of India during 2008-2014, where a total of 51 clinical epithelial tissue samples (vesicle/tongue/gum/foot epithelium) from sheep and 78 from goats were found positive for FMD virus (FMDV) serotype O in serotyping ELISA and multiplex reverse transcription-PCR. The VP1 region-based phylogenetic analysis demonstrated the involvement of O/ME-SA/Ind2001 lineage of serotype O virus in the outbreaks. The field viruses recovered from both small and large ruminant population during the same time period showed a close genetic relationship suggesting frequent inter-species transmission of virus. Since the disease often remains clinically camouflaged in small ruminants, the animals silently infected with FMD may pose potential threats to the in-contact livestock. Regular vaccination combined with surveillance and monitoring of protective antibody status in these species is therefore crucial to the effective control of FMD in the country.