Zika Virus in the UK

27/07/2017

It is very unlikely that there will ever be an outbreak of Zika Virus in the UK, simply because its vector, the aedes aegypti mosquito, which also carries dengue and yellow fever, cannot survive the weather in this country.

Nonetheless, as healthcare professionals, we need to be aware of diseases affecting other parts of the world. In an era of global travel, some patients will be planning foreign trips to areas where Zika is prevalent. We need to be able to offer them robust advice, which at the same time does not cause unnecessary alarm.

Zika was first identified in humans in 1952, although it only really hit the public conscience in 2015, during an outbreak in Brazil, when it was demonstrated that babies of mothers infected with the virus during pregnancy were twenty times more likely to be born with microcephaly. This is associated with irreversible brain damage and severe lifelong disability.

Unlike the mosquito which carries malaria, that which transmits Zika is active during daytime rather than the night. The incubation period, from infection to development of symptoms, is usually around 48 hours. In most cases, a mild, self-limiting condition similar to any other viral illness will ensue for up to 7 days, followed by complete recovery. Those at the extremes of ages or frail may be worse affected and occasionally need to seek medical advice. Otherwise supportive treatment, with increased oral fluid intake and regular simple analgesia is encouraged.

Where guidance needs to be offered is in regards to pregnant women, specifically those considering travel to an area where Zika has been identified, as well as any whose partner has returned from such a region.

As yet there is no vaccine to prevent Zika. The World Health organisation advises that anyone pregnant should consider postponing travel to high risk areas until after delivery. Zika can be transmitted in bodily fluids, and any male partner returning from an affected zone should use condoms for the entire pregnancy, or else abstain from sexual intercourse. Similarly any returning male partner should use condoms to prevent pregnancy for six months after travel. This advice is regardless of whether they may have been infected.

Despite this, if someone who is pregnant must travel to an area of moderate to high risk, basic precautions apply. Wear long clothing that covers the arms, legs and head. Use an insect repellent which contains up to 50% DEET. This is safe in pregnancy and for children older than 2 months. Although the mosquito is more active during the day, the advice is still to sleep under mosquito nets.

Any pregnant woman who attends after returning from foreign travel, and thinks she may have been exposed to Zika, should be immediately referred to an appropriate specialist, even if she has not had any symptoms. Laboratory testing will confirm the presence of infection. In this case, serial ultrasound scans will be offered to assess the growth of the foetus, as well as referral to an expert in foetal medicine if needed.