Illustration from a plate of four showing a patient developing yellow fever. Yellow fever is a tropical viral infection transmitted by mosquito bite. It causes fever, nausea, and headaches. A toxic form of the disease can lead to jaundice, internal bleeding, and death. Artwork from an 1820 French work by the French physicians Etienne Pariset (1770-1847) and Andre Mazet (1793-1821), documenting the 1819 yellow fever epidemic in Cadiz, Spain.