UK travellers have been warned after potentially fatal yellow fever cases were confirmed in nine countries. Since the start of 2026, there have been 95 confirmed cases worldwide, according to Travel Health Pro. The virus, spread by mosquitoes, is present in parts of Africa and South and Central America.
The affected countries include Bolivia, Brazil, Colombia, Ecuador, Peru, Venezuela, Burkina Faso, the Central African Republic, and Cameroon. Suspected cases have also been reported in Angola, Côte d’Ivoire, Gabon, Ghana, and Nigeria. In 2025, cases rose 5.6-fold compared with 2024, with 346 confirmed human cases and 143 deaths in the Americas alone.
Yellow fever symptoms typically appear three to six days after a mosquito bite and last three to four days. However, a small number of people develop more serious symptoms within 24 hours of feeling better, which can be fatal. The NHS advises seeking urgent medical help if you feel unwell after travelling to an affected area.
Travellers are urged to check the Travel Health Pro country pages for guidance and to consider vaccination before visiting at-risk destinations. Comprehensive travel insurance is also recommended.
