Senegal is grappling with its largest and deadliest outbreak of Rift Valley Fever (RVF) in decades, as health authorities confirm 140 human cases and 18 deaths as of October 10, 2025. The outbreak, which began in September in the Saint-Louis region, has since spread to Louga, Matam, and Fatick, alarming public health officials and communities alike. The rapid rise in cases and fatalities has prompted an urgent national response and raised concerns about the factors fueling the virus’s spread.
According to the Ministry of Health, the Saint-Louis region remains the epicenter, reporting 130 cases and 91 recoveries. Louga has documented four cases, Matam five, and Fatick one. Dr. Boly Diop, head of RVF surveillance at the health ministry, underscored the gravity of the situation, telling local media, “This is the first time Senegal has counted so many people affected.” The scale of the outbreak has exceeded anything the country has previously experienced, surpassing even the devastating epidemic of the 1980s that claimed more than 200 lives, as reported by local and international outlets.
RVF is a mosquito-borne viral disease that primarily targets livestock—sheep, goats, and cattle—but can also infect humans. The virus, which belongs to the Phlebovirus genus, was first identified in Kenya’s Rift Valley in 1931. Since then, it has periodically surfaced across sub-Saharan Africa and, on occasion, the Middle East. Outbreaks often follow periods of heavy rainfall or flooding, which create ideal breeding grounds for mosquitoes, especially Aedes and Culex species—the main vectors for the virus. According to the World Health Organization, the movement of infected livestock and surges in mosquito populations are key drivers of RVF’s spread.
In Senegal, the outbreak has hit hardest in the northern, livestock-producing regions. These areas are home to many breeders, farmers, and herders, who now find themselves at heightened risk. The virus can jump from animals to humans through two main routes: bites from infected mosquitoes and direct contact with the blood, organs, or bodily fluids of infected animals, particularly during slaughter, butchering, or birthing. “Herders, farmers, and slaughterhouse workers are most at risk,” the World Health Organization warns. Notably, human-to-human transmission has never been documented, and standard infection control practices are considered effective in healthcare settings.
The symptoms of RVF in humans typically emerge two to six days after infection. Most cases are mild or even asymptomatic, presenting as a flu-like illness with sudden fever, headache, muscle and joint pain, fatigue, and sometimes nausea or vomiting. These symptoms usually last about a week, after which most people recover as antibodies develop and the virus clears from the bloodstream. However, in a small percentage of patients, the disease can take a severe turn.
The severe forms of RVF are particularly alarming. Ocular complications, or eye lesions, occur in about 0.5–2% of patients, sometimes resulting in blurred vision or permanent vision loss if the macula is affected. Meningoencephalitis, a form of brain inflammation, affects less than 1% of cases and can lead to confusion, memory loss, seizures, or coma. The rarest but deadliest form is hemorrhagic fever, which also strikes less than 1% of patients. This form causes severe liver damage and internal bleeding, with a fatality rate of around 50%. Death in these cases typically occurs within three to six days after the onset of hemorrhagic symptoms, according to health ministry updates and the World Health Organization.
To combat the outbreak, Senegal’s government has mobilized a multi-sectoral response. On October 2, an intersectoral meeting was convened at the Ministry of Health and Public Hygiene, co-chaired by Dr. Ibrahima Sy, Minister of Health, and Dr. Mabouba Diagne, Minister of Agriculture, Livestock and Food Security. The meeting brought together technicians from the environment, livestock, and health sectors, focusing on strategies to contain the outbreak. High on the agenda were the livestock vaccination campaign and the urgent need to strengthen healthcare capacity, particularly in intensive care units.
Dr. Ibrahima Sy emphasized the importance of expanding healthcare resources to deal with severe cases. Meanwhile, Dr. Mabouba Diagne highlighted the need to support breeders and limit massive, uncontrolled herd movements, which have been identified as a major factor in the disease’s spread. The government has also launched a broad public awareness campaign, using newspapers, television, radio, and community media to inform the public about RVF and how to reduce the risk of infection.
Experts say that climate change is exacerbating the situation. Alternating heavy rains and hot weather have created perfect conditions for mosquito breeding, increasing the likelihood of outbreaks. “Climate change — with alternating heavy rains and hot weather — is creating ideal breeding conditions for mosquitoes, increasing the likelihood of outbreaks,” reported local media, echoing concerns voiced by international health agencies. These changing weather patterns are making it more difficult to predict and control the spread of mosquito-borne diseases like RVF.
The economic impact of the outbreak is also significant. RVF causes considerable losses in the livestock sector due to animal deaths and abortions in infected herds. Sheep and goats are particularly susceptible, but cattle and camels can also be affected. For rural communities that depend on livestock for their livelihoods, the outbreak is a devastating blow. The government’s response includes not only vaccination and vector control but also support for breeders and farmers facing economic hardship.
Health officials are urging preventive vaccination of livestock and enhanced mosquito control measures. The Ministry of Health has stressed the importance of early detection and isolation of cases, as well as the implementation of infection control precautions in healthcare settings. There is also a push to educate occupational groups—such as breeders, farmers, slaughterhouse workers, and veterinarians—about the risks and necessary precautions when handling animals or animal products. Consumption of raw or unpasteurized milk from infected animals is also discouraged, as it poses another route of infection.
While the majority of human infections remain mild, the risk of severe complications and death underscores the urgency of the current response. The government’s multi-pronged strategy—combining vaccination, healthcare strengthening, public awareness, and mosquito control—aims to curb the outbreak and prevent further loss of life. For now, communities across Senegal remain on high alert, hoping that swift action will bring the outbreak under control and spare the country from a repeat of the devastating epidemics of the past.
As Senegal faces this unprecedented challenge, the lessons learned and actions taken now may prove crucial not just for this outbreak, but for managing future threats from RVF and other emerging zoonotic diseases.
