Yellow fever seems to play a role in single, sudden breakouts of the disease. Three epidemiologically different infectious cycles occur, in which the virus is transmitted from mosquitoes to humans or other primates. In the "urban cycle", only the yellow fever mosquito "A. aegypti" is involved. It is well adapted to urban areas, and can also transmit other diseases, including Zika fever, dengue fever, and chikungunya. The urban cycle is responsible for the major outbreaks of yellow fever that occur in Africa. Except for an outbreak in Bolivia in 1999, this urban cycle no longer exists in South America. Besides the urban
Yellow fever a late-summer outbreak of yellow fever that quickly killed 68 of the 91 inhabitants. A local doctor concluded that some unspecified infectious agent had arrived in a package from New Orleans. 650 residents of Savannah, Georgia died from yellow fever in 1854. In 1858, St. Matthew's German Evangelical Lutheran Church in Charleston, South Carolina, suffered 308 yellow fever deaths, reducing the congregation by half. A ship carrying persons infected with the virus arrived in Hampton Roads in southeastern Virginia in June 1855. The disease spread quickly through the community, eventually killing over 3,000 people, mostly residents of Norfolk and Portsmouth.