Serological screening for porcine Japanese B encephalitis virus among commercial pigs in an urban abattoir in southwest Nigeria

Abstract

The inter-continental spread of Japanese encephalitis virus (JEV) to non-endemic regions is a continual impending threat with pigs implicated to play a major role in its transmission. Hence, the seroprevalence of the virus in pigs in a particular location is of utmost importance in the detection and control of the disease in a naïve population. A serological screening for JEV in slaughtered pigs at an urban abattoir in Ibadan, southwest Nigeria was conducted. Sera from 364 apparently healthy pigs were analyzed for the presence of JEV antibodies using a commercial ELISA kit. The results showed that none of the pigs had optimal JEV antibody titres, 42 (11.5%) had sub-optimal antibody levels while 322 (88.5%) were negative. Detection of sub-optimal JEV antibody levels in these unvaccinated pigs suggests exposure to JEV or related viruses. Also, drainages with dirt and stagnant water suitable for mosquito breeding were observed in this study. Considering that mosquito vector- and pig to pig- transmissions of JEV have been reported, these pigs, although with sub-optimal antibody levels can act as potential environmental source and play a role in transmission cycle of the virus in the study area. This therefore calls for continuous monitoring of the disease in pigs in Nigeria.