Foot and mouth disease outbreak in a pig farm at Nongpyiur, Meghalaya

Foot and mouth disease (FMD) is a highly contagious viral disease affecting cattle, pig, sheep, goat and other cloven-hoofed animals. Its manifestation varies in different species and accordingly, cattle are considered as the indicator host, small ruminants as maintenance hosts, and pigs as the amplifier hosts. This study investigates a suspected FMD outbreak in an organized pig farm at Nongpyiur, Shillong, Meghalaya during early 2020, where the animals exhibited clinical symptoms suggestive of FMD. During the investigation, clinical samples (n=15) along with serum samples (n=42) were collected from affected and in-contact apparently healthy animals. The clinical samples were processed and subjected to serotyping sandwich ELISA and RT-multiplex PCR, where 12 samples were found positive for serotype O. The serum samples were tested using in-house indirect 3AB3 NSP ELISA, where 32 (76.19%) were found positive for 3AB NSP antibodies. The serum samples were also tested in LPB ELISA that could not find any samples to be protective against all three serotypes. However, 28 samples were found to have a 4-fold spiked response against serotype O strain in comparison to other two strains fingering towards an evident circulation of serotype O in the farm. Contaminated feed caried by the vehicles from outside of state was suspected for the source of infection. Few FMD incidences in cattle of nearby areas as admitted by the farmers might also have been another contributing factor. Besides, the commuting of the pig handlers and care-takers from those local areas with a breach in biosecurity measures might have been the precipitating factor behind the disease outbreak in the farm.