Yellow fever is a mosquito borne disease caused by a virus from the Flaviviridae family, called the yellow fever virus. This virus is transmitted via female mosquitoes, especially the yellow fever mosquito called Aedes aegypti, in tropical and subtropical regions of South America and Africa. Africa is home to 90% of the cases of the disease and it is thought that it originated in this location. It is considered to be one of the most dangerous human diseases and causes fever, chills, muscle pain, headache and nausea. However, if the disease progresses to the second stage it can lead to liver damage, internal bleeding and death in 20% of cases. It is estimated that there are 200,000 cases a year and more than 30,000 deaths. Let’s find out how this potentially fatal disease is prevented and treated.
The most important method for preventing this disease is via vaccination. This vaccine was developed in 1937 by Max Theiler and has been used since commercially since the 1950’s. It is effective at preventing the disease in over 90% of those vaccinated. Vaccination lasts for more than 10 years with 81% of people still immune after 30 years. This vaccine is compulsory in many effected countries and is recommended to anyone visiting areas known for yellow fever.
There is no cure for the yellow fever virus after infection takes hold and at this stage vaccination is ineffective. The virus does not respond to antiviral drugs, which means the only course of action is to manage the symptoms. Hospitalization is recommended because the condition may deteriorate rapidly. Treatment in these cases is limited to rehydration and the management of pain with paracetamol (acetaminophen). Aspirin should not be used because of the internal bleeding that is sometimes seen in cases of yellow fever.