Tracking Rift Valley Fever Virus Exposure in Nigerian Livestock: A Call for One Health Action

Rift Valley fever (RVF) is an acute, notifiable emerging arthropod-borne disease with epidemic and zoonotic potential. It poses a significant threat to public health, livestock, and food security in some African countries, including Nigeria. A phlebovirus causes RVF, a large group of RNA viruses of the family Bunyaviridae with potential for international spread and bioterrorism. RVF virus can infect several domestic and wild animals as well as humans. It is transmitted through direct contact with infected blood or body fluids, animal tissue, infected mosquito bites, etc. In humans, RVF is mostly associated with mild flu-like symptoms, which may develop into severe symptoms including encephalitis, hepatic disease, and hemorrhagic fever, while in animals, it causes high rates of abortion and perinatal mortality. Limited information is available in Nigeria on RVF. To gain a better understanding of the infection in livestock, we screened 368 sera collected at slaughter from cattle (n = 184) and camels (n = 184) at Kano abattoir between May and June 2022 for RVF virus antibodies. The sera were analysed using a commercial ELISA kit. Among the samples examined, female animals constituted the largest at 69.02% (254/368), compared to males at 30.97% (114/368). An overall seropositivity rate of 8.15% (30/368, CI: 5.67-11.29) was recorded. The seropositivity was higher in cattle, 8.69% (16/184, CI: 5.233-13.45), than in camels, 7.60% (14/184, CI: 4.396-12.15). Based on sex, seropositivity was slightly higher in female animals, at 8.27% (21/254, CI: 5.33-12.15), compared to males, at 7.89% (9/114, CI: 3.19-13.99). Our findings revealed that cattle and dromedary camels presented for slaughter in the Kano abattoir, northern Nigeria, have evidence of exposure to RVF virus. This may be a potential risk to humans working at the abattoir and other animal populations. A One-Health investigation is recommended to understand the risk factors, associated vectors, and human exposure to the virus to mitigate the health and socioeconomic threats posed by RVF in the region.