WHAT IS YELLOW FEVER?

Yellow Fever is a viral infection spread by mosquitoes.  It is endemic in areas of Sub-Saharan Africa and in parts of South America.  The virus normally resides in primates.  Human infection occurs when a mosquito bites an infected primate and subsequently bites a person. The virus has an incubation period of 6 days before symptoms begin.

Initial symptoms of yellow fever may mimic the typical symptoms of common viral infections such as the common cold or the flu. These symptoms may include fever, headaches, muscle aches and possibly vomiting.

If the illness progresses, later symptoms may include abdominal pain, jaundice (a yellow pallor of the skin and/or eyes as the liver is affected) and bleeding from the eyes, nose, mouth and stomach.  Vomiting may include the vomiting of blood, which gave this disease its gruesome nickname of "the Black Vomit."  Treatment is symptomatic only, and the disease is potentially frequently fatal in those whose begin to exhibit these later symptoms.

URBAN YELLOW FEVER

Sometimes, mosquitoes begin to spread the yellow fever virus by biting infected persons (instead of primates) within a city.  This is called "Urban Yellow Fever."

PREVENTION OF YELLOW FEVER

The best way to prevent infection (if traveling in an area where  yellow fever is endemic) is to receive a vaccination.  Immunity occurs within 1 week for most people vaccinated.  The vaccination is effective for 10 years.

Yellow Fever is the only disease for which you may be required to show "proof of vaccination" against before you enter a country.  

Alice V. Coghill, M.D.

March, 2008