Zika Viral Disease

Updated: 20 August 2024

Context

Typical symptoms are:

low-grade fever
joint pain and/or pain in the eye sockets
rash (sometimes itching as well)
conjunctivitis / red eyes
headache
muscle pain.

The majority of infected individuals either don’t know they have the disease or the symptoms are very mild, lasting between 2 and 7 days.

Those with suggestive symptoms (as above) in known Zika affected areas are likely to be diagnosed without blood / laboratory testing. Tests for the disease aren't totally reliable, the best being the so-called PCR test. Those who develop symptoms whilst deployed are recommended to seek local medical attention and ask to be tested. Those who develop symptoms on return to home / UK should consult their GP. Routine testing for those who have been to Zika affected areas, but have remained asymptomatic, is not currently being recommended.

Serious complications and deaths from Zika are rare. However, recent increases in congenital anomalies (particularly microcephaly), Guillain-Barré syndrome, and other neurological and auto-immune syndromes are being reported in areas where Zika outbreaks have occurred. There is now a consensus in the scientific community that the Zika virus is the cause of the congenital anomalies described above.

The disease is currently spreading throughout the Americas, West Indies and Pacific Islands - list of affected countries. The disease has been reported in other countries, but these have been isolated cases arising from those returning from affected countries, and not as a result of active transmission within the country. Active transmission is reliant on the distribution of the Aedes aegypti mosquito (see Useful Documents).

Detailed information about the disease is available from the following sources:

About the virus / disease

Zika virus is transmitted by the bite of the female Aedes mosquito, most commonly Aedes aegypti
This mosquito bites during the day and evening / night time, so you need to protect yourself against bites at all times of the day.
This mosquito is rare in the UK as our climate is not consistently warm enough for it to breed - meaning that individuals who return to the UK with the virus cannot act as a reservoir for the infection of others.
There is no specific antiviral treatment for Zika.
There is currently no vaccine or drug to prevent Zika infection.

Key precautions

The following measures and advice are taken from credible authorities (see list above and recommended links) - the approach is precautionary as there is little evidence-based information at present. You should always seek advice from occupational health before you travel internationally:

Women travellers who are, or may be, pregnant (in any trimester) or planning to become pregnant and who might travel to areas where any mosquito-borne diseases such as chikungunya, dengue, malaria and Zika are known to occur, should avoid travel and not deploy to an area where active Zika transmission is being reported.
To lessen the risk of infection of the foetus, women travellers should avoid becoming pregnant for 8 weeks following their return from an infected area
Zika virus has been reported to have been transmitted through sexual intercourse, from men to women and then to the foetus, so males living in or travelling to infected areas need to consider this risk. To lessen the risk of infection, if they have been asymptomatic, male travellers should confine themselves to protected sex using condoms for 8 weeks following their return from an infected area, with this period increasing to 6 months for those who have had Zika fever - consult your GP or medical specialist.
If you have concerns about travelling then you should talk to your manager at the earliest opportunity.
For those individuals who do travel to, or live in, an area where active Zika transmission is occurring, take scrupulous measures to avoid mosquito bites during both daytime and night time hours, though be aware that some risk of being bitten will remain:

Regularly use insect repellents such as DEET (available from Safety Stores)
Cover limbs with long-sleeved tops and trousers
Keep windows and doors closed and sleep in air conditioned hotels when possible
Use insecticide impregnated nets if sleeping outside or in poor accommodation
If you can, avoid areas where there are high numbers of mosquitoes.

Prior to deployment to a country known to have active transmission:

Review the Country Pages within myRisks Information website - if necessary, speak to the High Risk Team
Consider Zika viral disease in your risk assessment
Ensure "Zika" is included in the title of your risk assessment form
Make sure all of those being deployed are individually named in the risk assessment
Continue to monitor Public Health information sources regularly in case of a change in the advice being given - see Recommended Links (www).

Advice to those returning from a Zika infected area

On the 2nd September 2016, the WHO reported that to date there have been no reports of confirmed cases of Zika virus among people who attended the Olympic Games and since their return
Should individuals develop the symptoms of Zika on return to the UK i.e. high temperature, muscle and/or joint aches, and/or a rash or sometimes conjunctivitis, they should consult their own GP or attend an NHS casualty department as soon as possible. The NHS will have access to testing facilities and public health advice that we do not readily have
We recommend that you avoid pregnancy and take appropriate contraceptive measures for 2 months following your return
For men only, if you have had Zika or Zika symptoms then the advice is that you should extend this period to 6 months
If you were to fall pregnant within the time frames above then whilst the likelihood of problems is small, you should consult your GP as soon as you are aware of your pregnancy and tell them about your travel to a Zika area
Based on Public Health England’s and the World Health Organisation's current advice, there is no indication to test individuals on return to the UK who have had not had any symptoms whilst abroad (asymptomatic). If you did have Zika symptoms whilst abroad and, for some reason, you were not tested at the time, then you can consult your GP who may advise testing in consultation with Public Health England
If you have any questions, you can talk to Occupational Health or consult your GP who will have access to PHE advice.