UK travellers have been warned about a surge in yellow fever cases, which rose 5.6 times in 2025 compared to the previous year. The potentially fatal viral disease is transmitted by mosquitoes across parts of Africa, Central and South America, and Trinidad in the Caribbean.
Rising Cases in South America
Travel Health Pro, a government advisory service, reported that yellow fever poses a risk in 13 countries and territories within South and Central America. In 2025, 346 confirmed human cases, including 143 deaths, were recorded across seven countries. This represents a 5.6-fold increase compared to 2024. Since the start of 2026, a total of 41 confirmed cases (including 18 deaths) have been reported across four countries: Bolivia, Colombia, Peru, and Venezuela.
While the majority of cases in 2024 were concentrated in the Amazon region, Travel Health Pro warned that cases have since been reported in a wider geographic area, including Sao Paulo State in Brazil and Tolima Department in Colombia. In Venezuela, recent human cases have occurred in an area not previously considered a risk for yellow fever. The risk of outbreaks remains high, with an ongoing outbreak in Colombia since mid-2024 resulting in 153 confirmed cases (including 62 deaths). The spread of cases near urban centres increases the risk of urban outbreaks.
Risk in Africa
Yellow fever cases are also being recorded across African nations. Travel Health Pro warned that the risk of transmission remains high in endemic areas, as mosquitoes that transmit the virus are common in many urban areas. This significantly increases the risk of rapid outbreaks, especially in heavily populated areas.
Advice for Travellers
Before travelling, individuals should check their risk of yellow fever, vaccine recommendations, and any certificate requirements using the TravelHealthPro Country Information pages. The yellow fever vaccine is recommended for all travellers aged nine months and older travelling to areas with risk, unless medically contraindicated. Some countries require an International Certificate of Vaccination or Prophylaxis (ICVP). Even if not required, the vaccine may be advised for personal protection.
The yellow fever vaccine is not available free on the NHS and typically costs between £60 and £85. Travellers can find their nearest vaccine centre online and should follow mosquito bite avoidance advice.
Symptoms
According to the NHS, yellow fever symptoms usually appear three to six days after being bitten by an infected mosquito, though sometimes longer. Initial symptoms resemble flu and include high temperature, headache, nausea, aches and pains, loss of appetite, and feeling generally unwell. These often last three to four days. A small number of people develop more serious symptoms within 24 hours of feeling better, such as jaundice, dark urine, stomach pain, and bleeding from the eyes, nose, mouth, or stomach. The NHS warns that these serious symptoms can be fatal. Anyone feeling unwell after travelling to a country where yellow fever is found should seek urgent medical attention.
