11. 1793 Yellow Fever Epidemic
While many think of Yellow Fever as a largely Caribbean disease, Philadelphia, Pennsylvania played host to a massive epidemic of the disease in 1793. August and September were widely considered “sickly season” throughout the coastal United States at the time, due to the common fevers that popped up throughout the season. However, no one was prepared for the Yellow Fever epidemic that hit during that season in 1793.
Due to many factors, including a slave rebellion in Saint-Domingue that led to numerous refugees, many of whom may have been carrying the infection and an unusually hot and wet summer, conditions were ripe for the outbreak of a mosquito-borne illness.
The first two to die were both new immigrants, one from Ireland and the other from Saint-Domingue, likely fleeing the slave uprising. It is quite possible that the refugee from Saint-Domingue was patient zero, as Yellow Fever was endemic in the area. Regardless of who was the first, the heavy mosquito population of that summer ultimately led to the deaths of over 5,000 people in only two short months.