Zika is a flavivirus that causes Zika fever. Other flaviviruses include dengue, yellow fever and the West Nile virus.
The Zika virus is primarily transferred through bites of the Aedes mosquito. Pregnant women can transmit the virus to their unborn child. In a number of cases, transmission occured between a man and woman or between two men. The Zika virus can also be transmitted through a blood transfusion.
The Zika virus was first detected in the Zika forest in Uganda (hence its name) in 1947. A first important outbreak was reported in 2007 in Micronesia and subsequently in French Polynesia in 2013. In 2015 an outbreak occurred in Central and South America and the Caribbean reaching certain states of the USA. Meanwhile is present in some countries in Asia, Africa and some islands of the Pacific.
Acute symptoms are vague and similar to many other flu-like illnesses:
The Zika virus can co-circulate in areas where dengue and chikungunya are present. All these diseases have similar clinical symptoms, and are thus often difficult to distinguish.
The symptoms occur a few days and up to 12 days after infection and last for about a week. Usually they are mild and disappear spontaneously. In most patients the disease is asymptomatic but in rare cases neurological complications have been described (Guillain-barré syndrome).
There is no treatment or vaccine. Patients who develop flu-like symptoms after returning from a region affected by Zika, dengue or chikungunya are advised to consult a doctor. He/she can get further advice from a specialist at the Institute of Tropical Medicine. The diagnosis can be confirmed by the National Reference Centre for Arboviruses at the ITM.
There is no vaccine against Zika and we urge travellers to protect themselves during the day with mosquito repellents, long sleeves and pants. Sexual transmission can be avoided by using a condom.
In October 2015, the Brazilian health authorities noted an increase in the number of newborns with microcephaly (reduced head size) compared to the years prior to the emergency of the Zika virus in Brazil. The virus can be transmitted to the unborn child during pregnancy and can cause defects like growth retardation, eye defects, ear defects, joint deformity and neurological defects such as psychomotor retardation and microcephaly (abnomally small skull). It can also lead to miscarriage.
Because of the link between Zika fever during pregnancy and poor outcomes for newborns, we issue the following travel alert:
We advise pregnant women and women trying to become pregnant during or after their travels, to postpone their voyage to areas where a Zika outbreak is ongoing (on the ECDC map the orange, red and striped regions).
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 gynecologist upon your return about your stay in an area where the Zika virus is endemic.
Couples wanting to become pregnant just after the return of one of the partners from an area with active Zika transmission can get counseling in a specialized centre and get tested if need be.
Pregnant women or couples with a pregnancy wish who have traveled to a Zika outbreak area can be tested. If one of them is or has been ill, the test should be performed as quickly as possible. If there have been no complaints, the best moment is 3 weeks after return. Contact your general practitioner, a department for infectious diseases or a travel health clinic for more information.
The ITM will further update its travel advice in case of new developments related to the spread of the Zika virus. Travellers can check the latest recommendations on this website.
If you still have questions after reading this article and the FAQ, please book a consultation.