Zika virus: should I worry about it?

The Zika virus is the latest in a line of 'new' tropical diseases to sweep across the globe and hit national headlines. In fact, it's not new; it was first identified in 1947 in a monkey from the Zika Forest in Uganda. Since then there have been a few small, isolated outbreaks of the disease in humans - but nothing compared to the rise in cases since 2014.

The risk of catching any disease is never the first thought when booking your dream holiday to a tropical paradise - but should we be worried about Zika?

The virus is transmitted through the bite of a mosquito - Aedes aegypti - and has slowly spread since 2007 through Central and South America, the Caribbean, South Asia and the Pacific islands. Zika isn't the only disease this mosquito can carry - dengue fever and Chikungunya virus are already prevalent in tropical countries. As yet there is no vaccine or medicine available in the UK that prevents these infections so the only protection is to avoid mosquito bites.

Most people infected with Zika will barely even notice, either getting no symptoms at all or mild, flu-like symptoms that get better within a week. Compared to most tropical diseases, Zika virus doesn't seem to pose too much of a risk.

So what is all the fuss about?

Well, the rise in cases of Zika in Brazil has coincided with a steep rise in cases of microcephaly - a rare birth defect where the baby has a much smaller head circumference than normal. Zika has not been conclusively proven to be the cause, but the evidence strongly suggests the virus can cross the placenta from mother to child during pregnancy and affect development.

The best advice for pregnant women is simply not to travel to a country where Zika is present. If travel is unavoidable then strict use of bite avoidance measures is essential, both day and night.

  • Regular use of an insect repellent containing 50% DEET (safe to use in pregnancy)
  • Plug-in insecticide tablets in your room help control mosquitos.
  • Wear long sleeved, loose clothing and long trousers (preferably light-coloured).
  • Sleep under a mosquito net unless your room is screened.
So, if I'm not pregnant I don't need to worry then?

Not quite. Unusually for a mosquito-borne disease there have been reports of Zika virus being sexually transmitted. One case involves a man, who didn't show any symptoms of Zika, infecting his partner three or four weeks after returning from a Zika-affected country. The virus has also been detected in semen up to two months after symptoms first appeared; we don't yet know how long it can persist for.

Even if you don't have any symptoms, couples should use condoms for at least eight weeks after returning from a Zika-affected country. This will prevent passing on the disease or getting pregnant whilst the virus could still be present. Men who do show symptoms need to use condoms for at least six months after returning.

**Always seek medical advice on potential health risks before travelling abroad. Anyone who develops flu-like symptoms after returning from a tropical country should see their doctor. **


Michael qualified as a pharmacist in 2000 and joined the Patient authoring team in 2016. Michael has over 15 years' experience working in community pharmacy and 5 years' experience as a medical information pharmacist, providing support on clinical, legal and regulatory issues, with special interests in travel medicine and pharmacy law. For five years he has worked as a knowledge assessor for BTEC Level 3 Diploma in pharmaceutical science and as a training facilitator for pre-registration pharmacists. Michael is a member of a pharmacy advisory panel and a multi-disciplinary steering group for the development of clinical resources for healthcare professionals.