1793 Philadelphia yellow fever epidemic Philadelphia forced evacuation of certain neighborhoods and placed refugees in supervised camps. After the epidemic, the city inspected all houses and destroyed those it deemed unhealthy. American doctors did not identify the vector of yellow fever until the late nineteenth century. In 1881 Carlos Finlay, a Cuban doctor, argued that mosquito bites caused yellow fever; he credited Rush's published account of the 1793 epidemic for giving him the idea. He said that Rush had written: "Mosquitoes (the usual attendants of a sickly autumn) were uncommonly numerous..." In the late 1880s, Finlay's theories were confirmed in Cuba by experiments of the
Yellow fever blood, hence the Spanish name for yellow fever, "vómito negro" ("black vomit"). There may also be kidney failure, hiccups, and delirium. The toxic phase is fatal in about 20% to 50% of cases, making the overall fatality rate for the disease about 3.0 to 7.5%. However, the fatality rate of those with the toxic phase of the disease may exceed 50%. Surviving the infection provides lifelong immunity, and normally no permanent organ damage results. Yellow fever is caused by the yellow fever virus, a 40– to 50--wide enveloped RNA virus, the type species and namesake of the family "Flaviviridae". It