Seroprevalence and Geographical Distribution of Rift Valley Fever in Small Ruminants in Mauritania: Evidence of Endemic Circulation and Regional Risk Hotspots

Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that causes severe illness in livestock and humans, with significant economic and health repercussions. Mauritania is considered an RVF focus in West Africa. A cross-sectional survey was conducted in 2023 in 12 of Mauritania’s 15 provinces. Serum samples from 849 small ruminants (428 goats and 421 sheep) were analyzed by ELISA for IgG and IgM antibodies against RVF virus. Logistic regression analyses were performed to assess associations between seropositivity and species, age, sex, season, and geographic location. In total, 14.1% of the animals tested were positive for anti-RVFV IgG antibodies. There was no association between anti-RVFV IgG positivity and the ruminant species, the sex, the age and the season. Hodh El Gharbi had the highest seroprevalence (40.5%), followed by Adrar (19.8%) and Tagant (19.7%). The lowest levels were recorded in Tiris Zemmour (2%) and Inchiri (3%). Only two animals tested positive for IgM, suggesting limited recent viral activity. This nationwide survey confirms widespread exposure of small ruminants to RVFV in Mauritania. Strengthening longitudinal serological monitoring and integrating ecological and entomological data within the “One Health” approach will be essential to preventing future epidemics and protecting animal and human health.