Yellow fever update

Yellow fever cases continue to be reported in Africa and South America

Yellow fever (YF) is a viral disease spread by mosquitoes in parts of Africa, Central and South America, and in Trinidad in the Caribbean. YF infection can cause a serious (haemorrhagic) illness that can be fatal. Vaccination and mosquito bite avoidance are the most effective ways to prevent the disease.

Region of the Americas

YF is a risk in areas of 13 countries and territories in South and Central America. In 2025, a high number of cases were reported from the region, with 346 confirmed human cases (including 143 deaths) from seven countries. This represents a 5.6-fold increase in cases compared to 2024 [1].

Since the beginning of 2026, a total of 79 confirmed cases have been reported from six countries: Bolivia, Brazil, Colombia, Ecuador, Peru and Venezuela [2].

In 2024, most YF cases were reported from the Amazon region. Although cases continue to be reported in this area, recent infections have also been reported in a wider geographic area, outside the Amazon region, including Sao Paulo State in Brazil and Tolima Department in Colombia [3]. Colombia has been experiencing an outbreak since mid-2024. The reporting of YF cases across a wider geographic area, including jungle transmission occurring close to urban centres, increases the risk of urban outbreaks [1]. Additionally, in Venezuela, recent reports suggest that human cases have occurred in an area not previously considered a risk for YF disease.

The risk of YF outbreaks in South America remains high [1–4]. While YF vaccination is one of the most successful public health interventions to prevent YF disease, the COVID-19 pandemic, among other factors, has led to a reduction of YF vaccine coverage in the local population [4].

African Region

YF remains a risk in 29 countries in Africa, and the region accounts for the majority of the worldwide estimated YF disease burden. Many countries in the region continue to report probable and confirmed cases. Since 2023, eight countries with no recent history of YF activity have detected new cases, indicating circulation of the virus in areas with low vaccination coverage [2].

In 2025, outbreaks were reported in Angola and Central African Republic [2].

Since the beginning of 2026, 16 confirmed cases have been reported from three countries: Burkina Faso, Central African Republic and Cameroon. Suspected cases have also been reported from five countries: Angola, Côte d’Ivoire, Gabon, Ghana and Nigeria [2].

Many of these infections are linked to sylvatic (jungle) transmission, where the virus circulates between mosquitoes and non-human primates in forested area, with spillover into rural communities with low vaccination coverage. These events place additional pressure on health services and increase the risk of cross-border spread [2].

The World Health Organization (WHO) advises that YF surveillance and reporting may be limited in some countries, meaning the true burden of disease is likely to be underestimated.

The risk of YF transmission remains high in endemic areas of Africa. The mosquitoes (Aedes spp.) that transmit YF are common in many urban areas in Africa, increasing the potential for rapid transmission and outbreaks, especially in heavily populated areas with low vaccination coverage [2, 5].

Advice for travellers

Before you travel

Check the TravelHealthPro Country Information pages for your destination to find out:

• whether there is a risk of YF
• whether YF vaccine is recommended
• whether you need a YF vaccination certificate to enter the country
• advice on general health risks, prevention advice, other vaccine recommendations, and malaria advice is also available on these pages

Comprehensive travel insurance is recommended for all travellers.

YF vaccine is recommended for travellers aged nine months and older, who are visiting countries or areas where there is a risk of YF transmission, unless there is a medical reason why they should not have the vaccine. A health professional at a designated Yellow Fever Vaccination Centre (YFVC) will carry out a risk assessment to help decide if YF vaccine is suitable for you.

Some countries may require travellers to show proof of YF vaccine by presenting an International Certificate of Vaccination or Prophylaxis (ICVP) for yellow fever on arrival and/or departure [6].

Even if a country does not require a YF certificate, vaccination may still be recommended for your own personal protection if there is a risk of YF at your destination.

You should also follow mosquito bite avoidance advice.

If you need advice about your risk of YF, whether vaccination is suitable for you, or if there are any certificate requirements for your journey, arrange an appointment with a designated YFVC. In the UK, you can find your nearest YFVC using our online YFVC Search Locator.

Advice for health professionals

Health professionals should advise travellers about their destination-specific risk of YF using the TravelHealthPro Country Information pages.

Travellers to countries with a risk of yellow fever transmission should be advised that YF is spread via mosquito bites and reminded of the importance of following insect bite avoidance measures both during the day and at night.

When undertaking YF risk assessment, health professionals should use the Yellow fever pre-vaccination checklist and Yellow fever vaccine: contraindications and precautions reminder.

Health professionals are also encouraged to access our Outbreak Surveillance section for information on current outbreaks. Please note that not all cases of disease or outbreaks are reported. Reports may be limited to outbreaks occurring outside recognised risk areas or seasons, or where case numbers are higher than expected.

In addition to the risk of YF, travellers may be exposed to other vaccine- and non-vaccine preventable diseases, including malaria. Travellers should be made aware of these risks and advised accordingly.

Health professionals can also call the NaTHNaC Advice Line for further advice.