In May 2015, Brazil announced an outbreak of the mosquito-borne Zika virus. Since then the Zika virus has spread widely with transmission detected in 52 countries/territories in the past 9 months. The UK defines areas with active Zika virus transmission according to the ECDC country list. To date, 27 confirmed cases of Zika virus infection have been reported in UK travellers linked to this outbreak.
Zika virus produces a mild clinical illness, similar to dengue fever that usually resolves in 4–7 days. Symptoms usually develop between 2-12 days and may include: fever, headache, conjunctivitis, rash, muscle tenderness and joint pain. There is no specific treatment, or vaccine and management is supportive only.
Zika Virus Infection and Microcephaly (smaller than normal head)
Concern has been raised by a large increase in the number of reported cases of microcephaly and central nervous system malformations in babies and fetuses in Brazil that coincide with the Zika virus outbreak. Seven countries or territories with Zika virus outbreaks have reported similar congenital malformations potentially associated with those outbreaks. Investigations by the World Health Organisation and local health authorities are ongoing to establish the nature of the relationship between Zika virus in pregnancy and these congenital anomalies.
Zika virus has been detected in semen two months after clinical symptoms of Zika; a small, but growing number of probable sexually transmitted cases of Zika virus infection (male to female) have been reported.
A recently published case report from France has detailed transmission from a symptomless man to his female partner between 21 and 30 days after return from a Zika endemic area. Symptomless male and non-pregnant female travellers should practice abstinence or use contraception including condoms during travel and for 8 weeks on return to reduce the risk of sexual transmission of Zika virus, particularly around the time of conception. Men who develop symptoms should continue to practice abstinence or use condoms for 6 months after return.
Advice for Travellers to Zika Virus Affected Countries
- Mosquito bite avoidance is strongly recommended.
- Advised to seek travel advice from a healthcare provider at least 6-8 weeks in advance of travel, but particularly important if pregnant or planning pregnancy.
- Strongly advised not to travel without adequate insurance – pregnant women should check with their travel insurance company that they are covered under the policy.
- Male and non-pregnant female travellers should practice abstinence or use contraception, including condoms during travel and for 8 weeks on return to reduce the risk of sexual transmission of Zika virus particularly during conception or pregnancy.
Women who are Pregnant
- Advised to postpone non-essential travel to countries with active Zika Virus transmission until the proposed link between Zika Virus and adverse pregnancy outcomes has been fully clarified.
- If travel is essential, should seek medical advice to help understand the risks involved in travel and therefore make a fully informed decision.
- During travel, strict bite avoidance is essential. Advise use of barrier methods to prevent potential sexual transmission of Zika virus from a male partner during travel and throughout the pregnancy.
- On return, early obstetric review is recommended even if well.