Causes
By Mayo Clinic staffYellow fever is caused by a virus that is spread by the Aedes aegypti mosquito. These mosquitoes thrive in and near human habitations where they breed in even the cleanest water. Most cases of yellow fever occur in sub-Saharan Africa and tropical South America.
Humans and monkeys are most commonly infected with the yellow fever virus. Mosquitoes transmit the virus back and forth between monkeys, humans or both. When a mosquito bites a human or monkey infected with yellow fever, the virus enters the mosquito's bloodstream and circulates before settling in the salivary glands. When the infected mosquito bites another monkey or human, the virus then enters the host's bloodstream, where it may cause illness.
- Monath TP. Yellow fever. http://www.uptodate.com/home/index.html. Accessed July 20, 2011.
- Yellow fever fact sheet. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvbid/yellowfever/YF_FactSheet.html. Accessed July 19, 2011.
- Hayes EB. Flaviviruses. In: Long SS. Principles and Practice of Pediatric Infectious Diseases Revised Reprint. 3rd ed. Philadelphia, Pa.: Churchill Livingstone Elsevier; 2009. http://www.mdconsult.com/books/page.do?eid=4-u1.0-B978-0-7020-3468-8..50224-8&isbn=978-0-7020-3468-8&uniqId=267749278-4#4-u1.0-B978-0-7020-3468-8..50224-8. Accessed July 19, 2011.
- Yellow fever frequently asked questions. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvbid/yellowfever/YF_FAQ.html. Accessed July 19, 2011.
- Yellow fever vaccine. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvbid/YellowFever/vaccine/index.html. Accessed July 19, 2011.
- Insect repellent use and safety. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvbid/westnile/qa/insect_repellent.htm. Accessed July 19, 2011.
- Vaccinations. Centers for Disease Control and Prevention. http://wwwn.cdc.gov/travel/content/vaccinations.aspx. Accessed July 20, 2011.
- Possible side-effects from vaccines. Centers for Disease Control and Prevention. http://www.cdc.gov/vaccines/vac-gen/side-effects.htm#yf. Accessed July 20, 2011.


Find Mayo Clinic on