Zika causes a mild fever, known as Zika fever. A travel alert is issued for large parts of South and Central America and the Caribbean. The Zika virus has also been detected previously in a number of other countries where the risk of infection is much lower.
In October 2015, the Brazilian health authorities noted an increase in the number of newborns with microcephaly (reduced skull size) compared to the years prior to the emergency of the Zika virus in Brazil. It has become clear that the virus can be transmitted to the unborn child during pregnancy. There are few well-documented cases in which microcephaly and other foetal abnormalities arose after the mother had Zika-like symptoms during the pregnancy. The virus was also detected in the tissue of newborns with birth defects born to women who have had Zika, and in the amniotic fluid.
A link between Zika fever during pregnancy and poor outcomes for newborns is therefore reasonably likely. However, further research is needed to get a full picture of the effect of the virus infection during pregnancy. As a precaution, ITM advises pregnant women and women with a pregnancy wish to postpone holiday travel to areas where a Zika outbreak is ongoing. If a trip to these areas cannot be avoided, it’s best to consult a doctor first to discuss preventive measures. It is important to inform your obstetrician or gynaecologist upon your return about your stay in an area where the Zika virus is endemic.
The ITM will further update its travel advice if there are new developments related to the spread of the Zika virus. Travellers can check the latest recommendations on www.reisgeneeskunde.be.
What is Zika virus?
Zika is a flavivirus like the dengue, yellow fever and West Nile viruses. It is transmitted by the Aedes mosquitoes that mostly bite during the daytime. The acute symptoms of the virus are vague, and similar to many other flu-like illnesses. In areas where Zika is endemic, dengue and chikungunya also co-circulate. Because the symptoms are similar, it is difficult to distinguish the different diseases from each other on a clinical basis. There is no specific treatment or vaccine. The only possible prevention consists of mosquito repellent measures, such as wearing long sleeves and trousers, and using insect repellents.
What to do when you show symptoms?
Patients who develop flu-like symptoms after a trip to an area where Zika, dengue or chikungunya are endemic should consult a physician who can, if necessary, further consult with an ITM doctor. Doctors can contact the National Reference Centre for arboviruses of the ITM to have the diagnosis confirmed. To date, one case of Zika in a Belgian traveller has been detected by the ITM laboratory.
Origin and distribution
The Zika virus was first detected in the Zika forest in Uganda in 1947 (hence its name). A first major epidemic was reported in Micronesia and in 2007 and in French Polynesia in 2013. Meanwhile, the virus has reached Central and South America and the Caribbean. We expect the epidemic will continue to spread.