Seroprevalence of Rift Valley Fever Virus Infection among Slaughtered Ruminants in Jos, North-Central, Nigeria
Joseph Anejo-Okopi1*, Obinna Oragwa Arthur2, Ocheme Julius Okojokwu1, Sarah Joseph1, Geoffrey Chibueze1, Joshua Adetunji1, Joseph Ameh Okwori3, David Ochola Amanyi4, Otobo I. Ujah5 and Onyemocho Audu6
Rift Valley fever (RVF) is a mosquito-borne emerging disease, capable of causing large epidemics in livestock accompanied by cases in humans, but with a complex cycle of transmission that makes it difficult to predict. The risk of infection in humans is more with livestock handlers who get occupationally exposed to Rift Valley fever virus (RVFV) because of frequent contact with infected vectors, animal body fluids and other tissues. We aimed to determine the prevalence of antibodies against RVFV in slaughtered ruminants in Jos, North-Central, Nigeria. Blood samples were collected from 100 livestock (cattle and goats) at selected slaughter locations in Jos Metropolis. Questionnaires were administered to obtain information on animal species, sex, and localities of origin. The blood samples were screened for RVFV antibodies using competitive Enzyme Linked-immunosorbent Assays (C-ELISA) to detect anti-RVFV IgG/IgM. Eleven out of 100 samples tested positive for anti-RVFV antibodies (prevalence=11%). Seropositive cases were more among cattle (16.0%) than goats (6.0%) (P=0.001). Seropositivity was also higher among the animals from Yan-shanu market, with 90.9% of the seropositive animals purchased from the said market. The mean duration of stay of animals at the abattoir/slaughter slab before slaughtering was not associated with the infection. The infection was more in females than males, though with no statistical significance. This study revealed high prevalence of RVFV infection in Jos, Nigeria, and highlights the endemic circulation of the virus despite the absence of clinical symptoms in animals sampled, suggesting the need to set up early warning surveillance and prevention/control strategies to mitigate the risk of unexpected outbreaks.