Infected mosquitoes spread Yellow Fever. Although Yellow Fever still impacts significantly on indigenous people it’s impact on travelers is minimal because of the effectiveness of the vaccination. Distribution and Transmission Yellow Fever is present in tropical Africa and South America. Signs and Symptoms. The main symptoms are fever, jaundice, hemorrhage and renal failure. Additional Information Yellow Fever vaccination is the only remaining vaccination that is required by the World Health Organization. This vaccination is documented on a Yellow Fever Certificate. This certificate is required by some countries before you enter.