Yellow Fever at Miami 55


identified as the carrier was then known as Stegomyia fasciatus;
today we know it as the Aedes aegypti.59
 This discovery explained several bits of time-honored yellow
fever folk wisdom. The Aedes aegypti was found to be an urban
mosquito which bred in stagnant collections of water commonly found
around human habitations: in discarded jars, cans, cisterns, roof drains
and catchment basins. This explained the predominence of yellow
fever in cities, as well as the fact that ships sometimes carried yellow
fever from tropical ports mosquitoes bred in the water casks and
bilge.60
 The belief that leaving the city before sunset and returning after
dawn to avoid contracting yellow fever was also explained by this discov-
ery the Aedes aegypti is a night biting mosquito. It became clear why
taking refuge in the mountains helped to avoid infection, and why the first
good frost usually marked the end of an epidemic the Aedes
aegypti is quickly killed by cold weather. The Reed Commission
found that the yellow virus must incubate in the mosquito's digestive
tract from nine to thirty days before the mosquito can pass it on,
which explained the delay between the Anderson case and the start
of the Miami epidemic. Finally, the close and confusing association
of yellow fever and dengue fever was clearly evident they are
both transmitted by the Aedes aegypti.61
 Whereas public health physicians welcomed the discovery, they
were slow to abandon their sterilization/fumigation stations and the
practice of quarantining vessels leaving tropical ports during the spring,
summer and fall. When Florida's final yellow fever epidemic oc-
curred in Pensacola in 1905, it was quickly contained by isolation of
patients under mosquito netting and vigorous measures to eradicate
mosquitos. However, even in 1905, a few physicians and many lay-
men insisted on extreme measures, such as requiring that Florida
oranges be shipped in screened boxcars when they passed through
Arkansas. The Florida ports of Apalachicola and Carrabelle even
refused to allow a cargo of brick and gasoline to be landed despite
the ship having been cleared by the State Board of Health.62


 Acknowledgements: The author is indebted to many individuals for
help. He is especially indebted to Arva Parks McCabe for encouragement,
astute editing and the use of her extensive library and photographic
archives. Others who gave assistance generously were Larry Wiggins,