Transmission Electron Microscope Image of Yellow Fever
Yellow Fever, a well-known pathogen, is a virus thought to originate in Central Africa. It has been confirmed to be around for about 300 years. Although there were quarantines in Boston in 1648 due to the suspected yellow fever disease, there wasn't a confirmed yellow fever outbreak until 1699, when yellow fever spread through North American settlements. The discovery of said disease cannot be pinpointed to a specific person and time, but most will credit it's discovery to James Carroll in 1900. Carroll was a U.S. army physician who allowed a mosquito carrying the virus to infect him. He then proved that they could carry the disease.