Serological evidence of the circulation of the Rift Valley fever virus in sheep and goats slaughtered in Yaounde, Cameroon

Background: Rift Valley fever (RVF) is an emerging mosquito-borne haemorrhagic fever disease capable of causing severe outbreaks with high mortality and morbidity in human, livestock, and wildlife species, particularly in Africa. The onset of the disease in humans is often preceded by epizootic circulation in animals. Therefore, this study was conducted to investigate the seroprevalence of Rift Valley fever virus (RVFV) infection in animals slaughtered in the "Marche huitieme" slaughterhouse in Yaounde, Cameroon. Methods: A cross-sectional study was conducted at the "Marche huitieme" slaughterhouse in Yaounde, Centre region of Cameroon in March 2020. Blood samples of two species of small ruminants (sheep and goat) were collected and processed. Serum was analysed for detection of RVFV IgG and IgM using commercial ELISA tests. Results: Of the 191 ruminants tested, RVFV IgG antibodies were positive in 10 (5.2%). Regarding categorization of the population based on the species and gender, sheep and female animal had the highest seroprevalence of 6.4% (3/47) and 7.0% (8/115), respectively. All sera from IgG antibodies-positive samples were negative to IgM antibodies. Conclusion: This study provides evidence of the circulation of RVFV in small ruminants sold and slaughtered at the "Marche huitieme" slaughterhouse in Yaounde and highlights the need to develop a surveillance system for this virus encompassing humans, livestock, wildlife, and vectors in Cameroon.