Mapping the Risk of Yellow Fever Infection

The World Health Organization coordinated a comprehensive, systematic review of the countries and areas at risk for yellow fever (YF) virus transmission. The review applied the following evidence to each country and area considered: human and non-human YF cases, human serology for anti-YF antibody obtained prior to widespread YF vaccination, altitude, vegetation, and vector distribution. The result was the categorization of countries or areas as endemic, transitional, low potential for infection, or no risk. This information was adapted to create a map that defined the areas where vaccination against YF may be recommended. Travel health professionals, countries, and public health bodies can use this information as they determine recommendations and requirements for vaccination. This paper reviews the process and outcomes of the review of YF risk, and places it in the context of providing YF vaccination.