Serological Investigation of Japanese Encephalitis Virus Infection in Commercially Reared Pigs, Southwestern Nigeria.

Japanese encephalitis virus (JEV) is a zoonotic arbovirus that causes abortion, stillbirth, and congenital defects in pigs, and epidemic encephalitis in humans. Currently, there is scarcity of information on JEV infection in pigs in Nigeria. Since the Culex tritaeniorhynchus vector of JEV is present in Nigeria and considering recent anecdotal reports of abortions and birth of weak piglets in some pig farms in southwestern Nigeria, there is a need for studies on the presence of the virus and its true burden among pig populations in the country. Serum samples (n=368) obtained from farm-reared pigs in four States of southwestern Nigeria were screened for JEV-specific IgG antibodies using a commercial ELISA kit. An overall JEV seropositivity of 35.1% (95% CI: 30.18 - 39.93%) was obtained, with detectable antibodies in pigs of all age groups, breeds, sex, and locations. Our results suggest natural exposure of these unvaccinated intensively reared pigs to JEV circulating silently in the swine population with significant association of the seropositivity with location (state/community in which the pig farms exist) and breed of the pigs studied. This first report of detection of anti-JEV antibodies in pigs in Nigeria indicates that JEV circulated among these pigs and underscores the need for active surveillance for JEV in humans, pigs, and mosquitoes to provide valuable epidemiological data for the design of effective control strategies against the virus, thus forestalling potential future outbreaks of the infection.

Molecular Detection of Peste des Petits Ruminants Virus (PPRV) in Goats and in Sheep in Ibadan, Oyo State, Nigeria.

Peste des petits ruminants (PPR) is a vaccine-preventable transboundary animal disease of goats and sheep majorly, and is regarded as a major constraint to small ruminant production especially in developing countries like Nigeria. Despite different strategies that have been employed to control PPR in Nigeria, cases of the disease are still reported in PPR-vaccinated and unvaccinated small ruminant farms. In this study, molecular detection of field PPR virus (PPRV) strains was carried out to determine the presence of PPRV. A total of 135 samples (45 oculo-nasal swabs and 90 tissue samples) were purposively collected between August and October 2020 from goats and sheep at the Akinyele live small ruminant market and at Akinyele and Amosun abattoirs in Ibadan, Oyo State, Nigeria. Using reverse transcriptasepolymerase chain reaction with primers targeting the partial N-gene of PPRV, 10 out of the 135 (7.4%) field samples yielded positive results. The results of this study reveal that PPRV currently circulates in Ibadan. These findings underscore the need for continuous PPR surveillance, more extensive characterization of circulating PPRV strains and the importance of consistent use of quality vaccines in the country to achieve more effective preventive and control strategies against the disease.