Metro Guard Mosquito Information

Yellow Fever

Yellow fever is an acute viral haemorrhagic disease transmitted by infected mosquitoes. The "yellow" in the name refers to the jaundice that affects some patients.  Up to 50% of severely affected persons without treatment will die from yellow fever.  There are an estimated 200 000 cases of yellow fever, causing 30 000 deaths, worldwide each year. 

The virus is endemic in tropical areas of Africa and Latin America, with a combined population of over 900 million people.  The number of yellow fever cases has increased over the past two decades due to declining population immunity to infection, deforestation, urbanization, population movements and climate change.  There is no cure for yellow fever. Treatment is symptomatic, aimed at reducing the symptoms for the comfort of the patient. Vaccination is the most important preventive measure against yellow fever. The vaccine is safe, affordable and highly effective, and appears to provide protection for 30–35 years or more. The vaccine provides effective immunity within one week for 95% of persons vaccinated.

Once contracted, the virus incubates in the body for 3 to 6 days, followed by infection that can occur in one or two phases. The first, "acute", phase usually causes 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.