author(s)
SR Pegu, DK Sarma, S Rajkhowa and M Choudhury

abstract
The objective of this study was to evaluate the prevalence of antibodies to four economically significant viral pathogens in domestic pigs (porcine Reproductive and respiratory syndrome (PRRS) virus, porcine parvovirus (PPV), swine influenza virus (SIV) and porcine circo virus (PCV2) through a serological study in swine herds of five NE states of India experiencing reproductive problems. A total of 1064 serum samples from pigs were tested for antibody to the above mentioned viruses using a commercial ELISA kit. All farms in this study were farrow-to-finish operations and do not use an all-in-all out system. The obtained results showed the presence of antibodies to PPV (10.15%), PCV-2 (11.56 %), PRRSV (0.84%) and SIV (3.94%) in serum samples. Except Mizoram other four states were seronegative to PRRS virus. Clinical signs in sows and gilts recorded were mostly anestrous, abortion, stillborn and mummified foetuses, small litter size and weak born piglets. A total of 86 foetuses and weak piglets were necropsied from different swine herds. Pathological changes recorded grossly were congestion in the body surfaces, internal organs with accumulation of serosanguinous fluid in the body cavities of some necropsied late term aborted foetuses. PCR confirmation of the tissue samples collected from foetuses and piglets was done for the presence of PCV-2 and PPV by a duplex PCR. The present study demonstrated the extensive circulation of porcine parvo virus and porcine circo virus type 2 among domestic pig populations of NE India. All seropositivity to PRRSV, PPV, PCV2 and SIV is due to natural infection, because neither commercial nor autogenous vaccines were available during the study period throughout the country, indicating that the infection was widespread. This serological survey confirms a significant role of viral pathogens causing reproductive problems in pig population of NE India.