Evidence of transboundary transmission of viral pathogens through pigs transported from Myanmar to Mizoram, India

Abstract

In Mizoram, pigs used to migrate through the porous international border from Myanmar. It is speculated that the migrated animals may act as potential carriers of various microbial pathogens. But so far no scientific evidence is available in this aspect. The present study was conducted on the detection of serum antibodies and molecular detection of classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus 2 (PCV2) and rotavirus in the pigs. A total of 204 blood and 209 rectal swabs were collected from apparently healthy pigs of Champhai district of Mizoram transported from Myanmar. All the serum samples were subjected to ELISA based detection of antibodies against CSFV, PRRSV and PCV2. The whole blood/serum/feces were processed for extraction of viral nucleic acids and subjected to PCR/RT-PCR for detection of CSFV, PRRSV, PCV2 and rotavirus. A total of 105 (51.47%), 12(5.88%) and 36 (17.65%) serum samples were found to be positive for antibodies against CSFV, PRRSV and PCV2, respectively. In addition, 17 (8.33%) sera were recorded positive for both CSFV and PCV-2 antibodies and 9 (4.41%) sera were positive for CSFV, PCV-2 and PRRSV antibodies. By specific PCR, group A rotavirus was found to be most prevalent (8.33%) followed by PCV-2 (7.84%), CSFV (4.41%) and PRRSV (0.9%). All the rotaviruses were detected as Group A only. Of the 204 animals, 2 (0.98%) pigs showed co-infection with all the four viruses under the study. A total of 5 (2.45%) pigs were positive for co-infection with CSFV and PCV-2 and 4 (1.96%) pigs were positive for co-infection with PCV-2 and rotavirus. The present study provided laboratory based evidence on transmission of porcine viral pathogens from Myanmar to Mizoram.