Yellow fever sequence, 19th century illustration. This portrait, the fourth in a sequence of four, shows a young man in the final stages of yellow fever, bleeding with bloody and black vomit. 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. This artwork is by Charles Philibert, Comte de Lasteyrie du Saillant (1759-1849). It is 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.