Serological evidence of hepatitis e virus activity among slaughtered pigs and in selected pig farms in Ibadan, Nigeria: Implications for zoonotic transmission ?

Abstract

Hepatitis E (HE) is endemic and of public health importance in many developing countries where poor sanitation condition has been identified as its major predisposing factor. In Europe and America, direct contact with pigs is linked with the presence of HE virus (HEV) in humans. However, despite poor sanitary conditions in many Nigerian communities, and established contacts between occupationally exposed individuals and pigs, limited studies have been conducted on HEV in pigs in Nigeria with unknown associated public health impact. Thus, this preliminary study was designed to investigate serologic evidence of HEV activity in pigs slaughtered at Bodija municipal abattoir and those reared on six swine farms in Ibadan, southwest Nigeria. The sera were screened for anti-HEV antibodies using a commercial ELISA kit that was developed based on a capsidderived  recombinant antigen of genotype 3 HEV. Overall, 57.4% (101/176) of the sera reacted against genotype 3 HEV with 31.3% (55/176) and 26.1% (46/176) of abattoir and farm pigs, respectively being seropositive. No significant differences in HEV seropositivity were observed between sexes and breeds but a significantly higher seroprevalence was obtained for farm pigs compared to abattoir pigs in the 7-12 months age group. Women and young girls were observed to be majorly involved in pig slaughtering at the abattoir, thus constituting an occupationally exposed  population that could be potentially infected and transmit the disease. These  findings highlight the need for large-scale investigations of pigs and individuals that are  occupationally at-risk individuals order to determine the actual burden of HEV infections in Nigeria.