DEAR DOCTOR: I read that hospitals in the United States might run out of yellow fever vaccine soon. Is yellow fever really an issue in this country?
DEAR READER: Yellow fever is a flulike illness spread by certain species of mosquitoes that are infected with the virus. It affects both monkeys and humans and is carried between the species by the infected insects.
Not everyone who contracts the virus develops symptoms. In less-serious cases, patients experience fever, chills, headache, muscle aches, nausea and vomiting. Jaundice, which causes the skin and whites of the eyes to appear yellow and can also be a symptom, is how the disease got its name.
In the small proportion of people who go on to develop a severe form of yellow fever – about 15 percent of those who are infected – the disease can cause uncontrolled bleeding and result in heart, kidney and liver problems. According to the World Health Organization, half of the severe cases of yellow fever are fatal.
The disease, which is believed to have originated in Africa, became an international problem in the 1600s, when shipping began to go global. The infected mosquitoes were transported throughout the world, and yellow fever epidemics began to occur.