Infectious diseases transmitted by other mosquitoes

Yellow fever

Yellow fever is an infectious disease caused by the yellow fever virus. The disease is found only in tropical regions of Africa and South America. The yellow fever virus is transmitted by the yellow fever mosquito (Aedes aegypti), by other mosquitoes of the genus Aedes and by mosquitoes of the genus Haemagogus. Both humans and monkeys can be infected with the virus. Mosquitoes can transmit the virus to humans by having themselves been infected by a person or a monkey. Infection through blood transfusion, organ transplantation, pregnancy or breast-feeding is also possible.

What are the symptoms and complications?

Approximately one infected person in ten becomes ill. Symptoms can range from a mild flu-like illness to a serious infection that can be fatal. After an incubation period Time between infection and appearance of symptoms. of 2 to 9 days, the first symptoms such as high fever, headaches and muscle aches appear. Most patients recover after 3 or 4 days. However, around 15-25% of patients fall ill again after a short recovery period, with severe symptoms such as jaundice, bleeding and shock. Young children are more susceptible to severe forms of yellow fever (affecting the brain). There is a high mortality rate among those who develop jaundice, with up to half of patients dying.

How is yellow fever diagnosed?

If the doctor suspects yellow fever, the diagnosis can be made by a blood test or a lumbar puncture (in cases of severe illness). Depending on the stage of the disease, different tests may be used, such as PCR Acronym for polymerase chain reaction, is a technique used in laboratories to amplify DNA fragments. This technique is used for rapid diagnosis of the presence of pathogens, for example. or serology This involves measuring antibodies (produced by the body in response to the presence of a pathogen) in a blood sample. . 

How is the disease treated and prevented?

There is no specific treatment for yellow fever, only symptomatic treatment. There is a highly effective vaccine against yellow fever. In some countries, vaccination is compulsory for all travellers. Prevention also involves avoiding mosquito bites.