General Information:
Yellow Fever is a viral infection that causes damage to the liver, kidney, heart and gastrointestinal tract. Major symptoms may include sudden onset of fever, yellowing of the skin (jaundice) and hemorrhage. It occurs predominately in South America, the Caribbean Islands and Africa. The disease is spread through bites of infected mosquitoes. Incidence of the disease tends to increase in the summer as the mosquito population increases, and it occurs year round in tropical climates.
Yellow Fever has two cycles: the sylvan cycle in which mosquitoes primarily spread the disease among forest-dwelling primates, and the urban cycle in which the infection is spread from human to human.
What causes yellow fever?
Yellow fever is caused by infection with yellow fever virus, which is transmitted by the bite of infected mosquitoes.
What is the basic yellow fever transmission cycle?
There are two kinds of yellow fever, spread by two different cycles of infection.
Jungle yellow fever is mainly a disease of monkeys. It is spread from infected mosquitoes to monkeys in the tropical rain forest. People get jungle yellow fever when they are bitten by mosquitoes that have been infected after feeding on infected monkeys. Jungle yellow fever is rare and occurs mainly in persons who live or work in tropical rain forests.
Urban yellow fever is a disease of humans. It is spread by mosquitoes that have been infected by other people. Aedes aegypti is the type of mosquito that usually carries yellow fever from human to human. These mosquitoes have adapted to living among humans in cities, towns, and villages. Their larvae grow in discarded tires, flower pots, oil drums, and water storage containers close to human dwellings. Urban yellow fever is the cause of most yellow fever outbreaks and epidemics.
What type of illness does yellow fever virus cause?
Illness ranges in severity from a self-limited febrile illness to severe hepatitis and hemorrhagic fever. Many yellow fever infections are mild, but the disease can cause severe, life-threatening illness. Symptoms of severe infection are high fever, chills, headache, muscle aches, vomiting, and backache. After a brief recovery period, the infection can lead to shock,
bleeding, and kidney and liver failure. Liver failure causes jaundice (yellowing of the skin and the whites of the eyes), which gives yellow fever its name. Severe yellow fever infections can be fatal.
What is the incubation period for yellow fever
The incubation period (time from infection to illness) is usually 3-6 days.
What is the mortality rate of yellow fever?
Case-fatality rates from severe disease range from 15% to more than 50%.
How is yellow fever treated?
There is no specific treatment for yellow fever. Treatment is symptomatic-rest, fluids, and ibuprofen, naproxen, acetaminophen, or paracetamol may relieve symptoms of fever and aching. Aspirin should be avoided. Infected persons should be protected from further mosquito exposure (staying indoors and/or under a mosquito net during the first few days of illness) so that they can't contribute to the transmission cycle.
Where does yellow fever virus occur?
The geographic range of the virus is South America and Africa. For information on current outbreaks, consult CDC’s Travelers’ Health website (www.cdc.gov/travel). Given the current yellow fever epidemics and the world wide distribution of Aedes aegypti, there is a risk of importation of yellow fever into new areas by infected travelers.
Past Epidemics
The epidemic that hit the United States in the 1850s wasn't the only time the world faced problems with Yellow Fever. Here is a brief summary of history's battles with the disease.
Europe 541-549
Fragile after the fall of Rome, Europe was further weakened by "Yellow Plague" (yellow fever). The Byzantine Empire suffered as well.
Cuba: 1762-1763
British and American colonial troops died by the thousands in the British expedition against Cuba between 1762 and 1763. Epidemics struck coastal and island communities throughout the area during the next 140 years, with 10% of the population dying as a result.
Haiti: 1802
In 1802, an army of forty thousand sent by First Consul Napoleon Bonaparte of France to Haiti to suppress the Haitian Revolution was dwindled out by an epidemic of yellow fever (including the expedition's commander and Bonaparte's brother-in-law, Charles Leclerc). Some historians believe Haiti was to be a staging point for an invasion of the United States through Louisiana (then still under French control).
The United States: 1850s, 1878
For more information on this, see the Yellow Fever in Bay Ridge page.
Panama: 1902
The building of the 51 mi Panama canal was plagued by problems, including disease, particularly malaria and yellow fever. By the time the canal was completed, a total of 27,500 workers are estimated to have died in the French and American efforts. This was actually a huge turning point in the history of yellow fever as the causes of it had recently been discovered by Dr. Walter Reed in Cuba (1880s). Thanks to Reed's findings (which were based on those of Carlos Finlay, a Cuban scientist who first discovered how Yellow Fever spread), workers were able to gain control over the disease, allowing the canal to be finished despite previous setbacks.
↑ All of the following information is from The Center for Disease Control and Prevention
