Historically, yellow fever has been the cause of major epidemics worldwide. During the 1800s, more than half of the French army fighting in the Haitian Revolution died from a yellow fever outbreak. Spain also had a major epidemic of yellow fever in the 19th century, and other major outbreaks have been reported throughout the world. In areas of the world such as the Caribbean, Africa and South America, yellow fever has had a significant impact on the outcome of historical events.
Yellow fever is transmitted to humans by infected mosquitoes. Caused by the yellow fever virus, which is considered a flavivirus, yellow fever can manifest in forms ranging from a relatively insignificant illness to a severe conditions. The disease largely affects populations in South America and Africa, where the vaccine is not readily available. Once contracted, there is no cure for yellow fever.
During the initial phase of yellow fever, symptoms include chills, fever, headache, muscle aches, back pain, fatigue, nausea and weakness. Symptoms generally appear within a week of exposure. There is often a period after this initial phase when symptoms recede. The fever returns as the toxic phase begins, and the patient develops more severe symptoms. During this phase of yellow fever, symptoms may include black vomit, nosebleeds, bleeding from the mouth and severe bruising. During the final stages of the disease, persons with yellow fever may exhibit metabolic acidosis, cardiac arrhythmia, hypertension and shock.
Although the last reported case of yellow fever in North America was in the early 1900s, travelers occasionally contract the disease in other countries. Regions of the world that often suffer from yellow fever include South America and Africa. In these regions, populations of unvaccinated nationals are often struck by yellow fever and experience a large number of preventable deaths.
If you are traveling to regions of South America or Africa that are known for yellow fever, the best prevention is the yellow fever vaccine, which is considered effective for ten years. When traveling, be sure to use mosquito repellent and sleep with mosquito netting around your bed. When outside, wear long-sleeved clothing and long pants to minimize the amount of exposed skin.
