Since September 20, when the first Rift Valley fever (RVF) cases were reported in northern Senegal, hundreds of confirmed cases and dozens of fatalities have been reported.
Mauritania
Between 27 September and 30 October 2025, a total of 44 confirmed human cases of RVF, including 14 associated deaths were reported in eleven of the 15 regions, three of which share international borders: Assaba (bordering Mali to the south), Brakna and Trarza (both bordering Senegal along the Senegal River).
Senegal
Between 20 September and5 November 2025, the Republic of Senegal reported a total of 397 confirmed human cases of RVF, including 29 deaths from nine regions.
There are also a number of animal outbreaks in each neighboring country. In Mauritania, the Ministry of Animal Resources reported a total of 62 animal outbreaks, with 235 positive samples out of 1106 collected and tested. This includes goats and dromedaries.
In Senegal, As of 29 October 2025, a total of 160 confirmed animal cases of RVF have been reported in sheep, goats and cattle in seven regions of Senegal: Dakar, Fatick, Louga, Matam, Saint-Louis, Tambacounda and Thiès. In addition, 640 animal abortions were reported in three regions.
Rift Valley fever (RVF) is a viral zoonotic disease primarily affecting domestic animals in sub-Saharan Africa, including cattle, sheep, goats and camels. Human infection may occur through bites from infected mosquitoes, however the majority of cases result from direct contact with the blood, tissues or organs of infected animals. Occupational groups at highest risk include livestock breeders, farmers, slaughterhouse workers and veterinarians. Humans can become infected by consuming unpasteurized or undercooked milk from infected animals. To date, no human-to-human transmission of RVF has been documented.
While RVF often leads to severe illness in animals, its impact in humans varies, ranging from mild flu-like symptoms to severe hemorrhagic fever that can be fatal. The majority of the infected individuals experience no symptoms or only mild illness, characterized by fever, general weakness, lower back pain and dizziness. However, a small percentage of patients (about 2%) progress to a severe form of the disease, which may manifest in one or more of the following three clinical presentations: ocular form (involving inflammation of the eye), meningoencephalitis (inflammation of the brain), and hemorrhagic form (bleeding).