FACTS ABOUT YELLOW FEVER

Yellow fever is an acute viral hemorrhagic disease transmitted by infected mosquitoes. The “yellow” in the name refers to the jaundice that affects some patients.

Symptoms of yellow fever include fever, headache, jaundice, muscle pain, nausea, vomiting and fatigue.

A small proportion of patients who contract the virus develop severe symptoms and approximately half of those die within seven to 10 days. The virus is endemic in tropical areas of Africa and Central and South America.

Since the launch of the Yellow Fever Initiative in 2006, significant progress in combating the disease has been made in West Africa and more than 105 million people have been vaccinated in mass campaigns. No outbreaks of yellow fever were reported in West Africa during 2015.

Large epidemics of yellow fever occur when infected people introduce the virus into heavily populated areas with high mosquito density and where most people have little or no immunity, due to lack of vaccination. In these conditions, infected mosquitoes transmit the virus from person to person.

Yellow fever is prevented by a safe, affordable and effective vaccine. A single dose of yellow fever vaccine is sufficient to confer sustained immunity and lifelong protection against yellow fever disease and a booster dose of the vaccine is not needed. The vaccine provides effective immunity within 30 days for 99 per cent of people vaccinated.

Good supportive treatment in hospitals improves survival rates. There is currently no specific antiviral drug for yellow fever.