Infectious diseases transmitted by the tiger mosquito

Zika

Zika is a disease caused by the Zika virus. The virus originated in Africa and has since spread to South-East Asia and certain Pacific islands. In May 2015, a major epidemic began in Brazil and the Zika virus has since spread across the American continent. Now that the tiger mosquito is established in southern Europe, small Zika epidemics are occurring (for example in France). In Belgium, only imported cases have been diagnosed in travellers from regions where the virus is circulating.

The Zika virus is transmitted by the tiger mosquito (Aedes albopictus) and by the mosquito that also transmits yellow fever (Aedes aegypti). In addition to mosquito bites, the virus can also be transmitted from mother to child during pregnancy, by blood transfusion and by sexual contact (the virus can persist in sperm).

What are the symptoms and complications?

Around one in four or five people infected with the Zika virus develops symptoms, after an incubation period Time between infection and appearance of symptoms. of between 3 and 12 days. Symptoms are generally mild and include (moderate) fever, headaches, burning or numbness in the hands or feet, muscle and joint pain, skin rashes and eye problems. Gastrointestinal problems may also occur. Symptoms generally disappear within a few days to a week.

Symptoms may be more severe in people with chronic illnesses or reduced immunity. Infection during pregnancy can lead to birth defects in the baby (in particular microcephaly, i.e. an abnormally small skull) or miscarriage. Another possible complication of Zika is Guillain-Barré syndrome (muscle weakness).

How is Zika fever diagnosed?

If the doctor suspects Zika, the diagnosis can be made by a blood test. 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 Zika; mild symptoms are treated symptomatically with painkillers. Given the potential complications, a pregnant woman who thinks she may have contracted Zika should contact a doctor. There is no vaccine against the Zika virus. Prevention involves avoiding mosquito bites and using a condom during sexual contact. The use of a condom by travellers returning from an area where Zika is present is particularly important if the sexual partner is pregnant and until the end of the pregnancy.