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 vaccine shortages in vaccine supplies. Demand for yellow vaccine for preventive campaigns has increased from about 5 million doses per year to a projected 62 million per year by 2014. UNICEF reported in 2013 that supplies were insufficient. Manufacturers are producing about 35 million of the 64 million doses needed per year. Demand for the yellow fever vaccine has continued to increase due to the growing number of countries implementing yellow fever vaccination as part of their routine immunization programmes. Recent upsurges in yellow fever outbreaks in Angola (2015), Democratic Republic of Congo (2016), Uganda (2016), and more recently in Nigeria