Yellow fever is an acute viral haemorrhagic disease transmitted by Aedes mosquitoes. The “yellow” in the name refers to the jaundice that affects some patients.
There are an estimated 200 000 cases of yellow fever causing 30 000 deaths worldwide each year.
The virus that causes yellow fever is endemic in tropical areas of Africa and Latin America where a combined population of over 900 million people lives. Small numbers of imported cases occur in countries free of yellow fever.
Symptoms of the disease include fever, muscle pain with prominent backache, headache, shivers, loss of appetite, and nausea or vomiting. Most patients improve and their symptoms disappear after 3 to 4 days.
However, 15% of patients enter a second, more toxic phase within 24 hours of the initial remission. High fever returns and several body systems are affected. The patient rapidly develops jaundice and complains of abdominal pain with vomiting and internal bleeding. Half of these patients die within 10 to 14 days.
There is no specific treatment for yellow fever, only supportive care to treat dehydration, respiratory failure and fever.
Vaccination is the most important preventive measure against yellow fever. The vaccine is safe, affordable and highly effective. A single dose of yellow fever vaccine is sufficient to provide life-long protection against the disease.