Nigeria, eight other African countries record 67 yellow fever cases, 18 deaths — WHO

Between January and October 2026, Nigeria and eight other African countries reported confirmed yellow fever infections. Together, they recorded 67 cases, including 18 deaths. The countries were Burkina Faso, Cameroon, the Central African Republic, Côte d’Ivoire, Ghana, Guinea, Liberia, Nigeria and Togo. The figures were the latest available to the WHO as of 12 October.

Transmission was concentrated in parts of West Africa, including communities near international borders. Côte d’Ivoire reported 30 cases and 10 deaths, while Burkina Faso recorded 15 cases and three deaths. Nigeria recorded four cases and one death. The presence of cases across nine countries indicates wider transmission across the region.

The WHO assessed the regional public health risk as moderate on 27 October, while global risk remained low. It said further cases are likely because of immunity gaps, uneven surveillance, insecurity and difficult access to some communities. Countries are strengthening testing, surveillance, vaccination and community engagement.

The nine affected countries reported 67 confirmed yellow fever cases and 18 deaths between January and October 2026. Côte d’Ivoire had the highest recorded burden, with 30 infections and 10 deaths. Burkina Faso followed with 15 cases and three deaths. Together, these two countries accounted for most of the confirmed infections and deaths in the report.

Cameroon recorded nine cases and one death. Nigeria and Ghana each reported four cases, but Ghana recorded three deaths while Nigeria recorded one. The Central African Republic had two cases, and Liberia had one laboratory-confirmed case. Guinea and Togo each reported one case, with no deaths among confirmed cases in those three countries.

The figures reflect information available to the WHO as of 12 October 2026. The organisation warned that additional cases remain likely because vaccination gaps, surveillance difficulties, insecurity and limited resources can delay detection and response. The overall regional risk was assessed as moderate.

Yellow fever is an acute viral disease transmitted through the bite of an infected mosquito. The infection can cause fever, headache, body aches, nausea, vomiting and weakness. It matters because some infections become severe and can threaten several body systems, especially where vaccination coverage is low.

About 15 per cent of infected people develop severe illness, according to the WHO. Severe disease may involve recurrent high fever, jaundice, bleeding, shock and organ failure. Approximately half of patients who enter this severe phase die within seven to 10 days. The virus spreads when infected mosquitoes bite people.

There is no routinely recommended specific antiviral treatment, so clinical care is largely supportive. Vaccination is the most effective preventive measure. The WHO says one dose provides lifelong protection. It also recommends mosquito control, stronger surveillance and public awareness of symptoms and prevention measures.

Cross-border travel increases risk because people moving for trade, farming, livestock and mining can carry infection between affected and neighbouring countries. The WHO also identified competent mosquito vectors in these areas. When infected mosquitoes are present, they can transmit the virus through bites and help establish transmission in new communities.

Outdoor work adds exposure because people in forests, forest-edge areas, farms and mining sites may spend more time where infected mosquitoes are found. Environmental conditions can favour mosquito spread. Frequent movement can then connect rural, forested and border communities. Uneven vaccination makes this more dangerous because some populations have less immunity to stop transmission.

The risk is highest among unvaccinated people, mobile and cross-border populations, rural and forest-edge communities, and people working in agriculture, mining or forests. The WHO is supporting surveillance, laboratory testing, vaccination campaigns, mosquito control and risk communication in affected and high-risk areas.

If yellow fever reaches a densely populated city or peri-urban area with low vaccination coverage, the WHO warns that a larger outbreak could occur. More people would be vulnerable because immunity gaps would leave fewer barriers to transmission. This could turn an infection introduced from another area into a wider public health emergency.

The mechanism involves infected mosquitoes biting susceptible people. In a crowded urban or peri-urban setting, many vulnerable residents may live near one another, while mosquito vectors can continue spreading infection. Cross-border and mobile populations could also help introduce the virus into areas that have not recently experienced transmission.

Such an outbreak would put additional pressure on public health response systems. The WHO said continued transmission and further cases are likely in the region because of surveillance and laboratory challenges, insecurity and limited resources. Maintaining routine immunisation, conducting campaigns and improving mosquito control can reduce this risk.

Health authorities are working to detect infections earlier and respond before transmission expands. Affected countries, supported by the WHO and other partners, are strengthening disease surveillance, investigating suspected cases and conducting laboratory tests. These actions help identify where the virus is present and guide response activities.

Containment efforts include community engagement, risk communication and vaccination in affected and high-risk areas. Authorities are also intensifying efforts to identify infections and improve mosquito control. Routine immunisation and preventive or outbreak-response campaigns are important because a single yellow fever vaccine dose provides lifelong protection, according to the WHO.

The organisation also called for stronger public awareness of symptoms and prevention measures. It advised at-risk countries to maintain high vaccination coverage and urged international travellers aged nine months and above visiting risk areas to get vaccinated. These measures are especially important where surveillance is difficult, resources are limited or communities are hard to reach.

An outbreak depends on contact between infected mosquitoes and people who can become infected. When competent mosquito vectors are present, they can spread yellow fever through bites. Human movement can carry infection into new areas, while outdoor work and forest exposure can increase contact with mosquitoes. More susceptible people create more opportunities for transmission to continue.

Vaccination changes that pattern by reducing the number of people vulnerable to infection. The WHO identifies vaccination as the most effective preventive measure and says one dose provides lifelong protection. If coverage is uneven, immunity gaps remain, especially among rural, forest-edge, mobile and cross-border populations. Mosquito control can further reduce opportunities for infected bites.

The balance is currently concerning in parts of Africa. The WHO assessed regional risk as moderate and said additional cases are likely. Strong surveillance, laboratory testing, vaccination, mosquito control and public awareness can help outbreaks stop before they reach densely populated areas with low coverage.