Yellow fever is one of the most dangerous mosquito-borne diseases — severe cases have a 20-50% fatality rate. The good news: it is also one of the most preventable. A single vaccine dose provides lifetime protection, and many countries require proof of vaccination for entry.
The disease is endemic in tropical regions of Africa and South America, transmitted by Aedes and Haemagogus mosquitoes. Urban outbreaks can be explosive when unvaccinated populations are exposed. Sylvatic (jungle) transmission cycles also maintain the virus in forest environments.
Vaccination is the single most important precaution. The yellow fever vaccine is safe, highly effective, and available at travel clinics worldwide. Some countries will refuse entry without a valid International Certificate of Vaccination.
Aedes aegypti (urban), Haemagogus and Sabethes species (sylvatic/jungle cycle in the Americas).
Unvaccinated travelers to Africa and South America face the highest risk. Severe cases have a 20-50% fatality rate, but the vaccine is extremely effective and widely available at travel clinics.
Yellow Fever is recorded in 43 countries in our database. Click any country for the full Mozzwise briefing covering local seasonality, regional risk, and prevention.
Disease information is sourced from WHO, CDC, ECDC, and OpenDengue. Not medical advice. Personal decisions on diagnosis, treatment, vaccinations, or medication belong with a qualified healthcare professional.