1793 Philadelphia yellow fever epidemic 1793 Philadelphia yellow fever epidemic During the Yellow Fever Epidemic of 1793 in Philadelphia, 5,000 or more people were listed in the official register of deaths between August 1 and November 9. The vast majority of them died of yellow fever, making the epidemic in the city of 50,000 people one of the most severe in United States history. By the end of September, 20,000 people had fled the city. The mortality rate peaked in October, before frost finally killed the mosquitoes and brought an end to the epidemic in November. Doctors tried a variety of treatments, but knew neither
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