UK travellers are facing renewed warnings about yellow fever as cases surge across South America and Africa, with 52 residents already placed on alert ahead of planned trips. Since the start of 2026, 41 confirmed cases and 18 deaths have been reported in Bolivia, Colombia, Peru and Venezuela alone, marking a sharp continuation of a trend that saw infections jump 5.6-fold in 2025 compared to the previous year.
The rise is not confined to remote jungle zones. Health officials note the virus is spreading beyond its traditional strongholds in the Amazon basin, with confirmed cases now appearing in urban-adjacent areas such as Sao Paulo State in Brazil and Tolima Department in Colombia. In Venezuela, infections have emerged in regions previously considered low-risk, suggesting the mosquito-borne disease is expanding its geographical footprint.
Travel Health Pro, the UK government’s travel health advisory service, has identified 13 countries and territories in South and Central America where yellow fever poses a risk, although also flagging ongoing transmission across multiple African nations. The warning extends to Trinidad in the Caribbean, completing a broad swathe of territory where the virus remains endemic.
Symptoms typically emerge three to six days after an infected mosquito bite, beginning with fever, headache and muscle pain before potentially progressing to jaundice, internal bleeding and organ failure. The disease carries a high mortality rate in severe cases, and there is no specific antiviral treatment — care is supportive, making prevention critical.
Despite the vaccine’s proven effectiveness, concerns persist over declining immunisation coverage in some endemic regions, a trend officials link in part to disruptions caused by the COVID-19 pandemic. Lower vaccination rates in local populations increase the risk of urban outbreaks, particularly as the virus shows signs of adapting to transmission near densely populated centres.
For UK residents, the alert serves as a reminder to consult official travel health resources before booking trips. Travel Health Pro’s country-specific pages detail vaccine requirements, risk levels and preventive measures, including mosquito bite avoidance through repellent use, protective clothing and screened accommodation.
Do I need a yellow fever vaccine if I’m only visiting cities in affected countries?
Yes, if the country is listed as having a risk of yellow fever transmission, vaccination is advised regardless of whether you plan to stay in urban or rural areas, as the virus has been detected in cities and surrounding zones in recent outbreaks.
How long does the yellow fever vaccine last, and do I need a booster?
A single dose of the yellow fever vaccine provides lifelong immunity for most individuals, and boosters are not routinely recommended unless specific health conditions or travel circumstances warrant review by a medical professional.
