Yellow fever is in a person's blood three to six days before symptoms begin and five days after. The acute stage presents as fever, severe headache, muscle pain, chills, anorexia, nausea, and vomiting. These symptoms last three to four days, after which most people recover. About 15% of those infected develop jaundice, high fever, and bleeding. In 10–14 days, 20–50% of those with severe disease go into shock and organ failure and die in 10–14 days. If they live, recovery may take many months.
There is no specific antiviral treatment for yellow fever. Vaccination is highly recommended for ages 9 months and older. The vaccine has been available for many years and is considered safe and effective.
