Sciensano is responsible for the epidemiological surveillance of malaria in humans in Belgium.
Malaria is an infectious disease transmitted by mosquitoes and caused by the parasite Plasmodium. Five different species of the malaria parasite cause human infections (Plasmodium falciparum, P. vivax, P. malariae, P. ovale and P. knowlesi). These species are distributed over all (sub-)tropical regions of the world and cause numerous cases of malaria and deaths around the world, particularly among children under 5 years of age in Africa.
What is malaria?
- Malaria is an infectious disease transmitted by some Anopheles mosquitoes and caused by the parasite Plasmodium.
- Malaria has not been endemic in Europe since the 1970s, thanks to medical treatment and the fight against breeding sites and mosquitoes. However, due to the presence in Europe of mosquito species that can act as vectors, there are still occasional local epidemics, such as in Greece (in 2011-2012).
- In Europe, however, malaria remains mainly an imported disease, i.e. contracted by travellers during stays abroad.
- In addition to transmission by mosquitoes, malaria can also be transmitted through blood transfusions, during pregnancy and through the reuse of contaminated needles.
- After an incubation period of 10 to 14 days on average, symptoms appear such as:
- fever with chills
- and muscle pain.
- Depending on the type of Plasmodium, fever spikes can occur every 48 hours (malaria tertiana or third-day fever, with P. vivax or P. ovale) or every 72 hours (malaria quartana or fourth-day fever, with P. malariae).
- The form caused by P. falciparum, also called “malaria tropica”, causes an irregular fever and is the most severe and can even be fatal.
- Young children, pregnant women and people with HIV/AIDS are more likely to develop a severe form.
- The parasites P. vivax and P. ovale can remain dormant in the body and reactivate months or years after infection, again causing symptoms. People who live in areas infected with malaria and are regularly exposed to it can develop a form of immunity that reduces or eliminates symptoms if infected. This protection disappears when the exposure ceases for a certain time.
Diagnosis, treatment and prevention
- Anyone who develops a fever within a few months of returning from an endemic area for malaria should consider the possibility of malaria. Even if the trip took place several months beforehand, it is still advisable to talk to your doctor about it. If the doctor suspects malaria, the diagnosis can be established by way of a blood test. Depending on the stage of the disease, different tests can be used, such as microscopic examination, a PCR test and an antigen test.
- A rapid diagnosis makes it possible to set up the appropriate treatment, depending on the type of Plasmodium.
- There are also medicines that can be taken preventively when travelling to endemic areas and that prevent severe forms of malaria (chemoprophylaxis). In addition, prevention is also done by avoiding mosquito bites.
- Recently, a vaccine has been developed that is recommended by the World Health Organization (WHO) for children living in areas where P. falciparum malaria is prevalent, such as in sub-Saharan Africa. This vaccine is not available to travellers.