Zika virus: preventing infection by sexual transmission
Guidance on the likelihood of sexual transmission of Zika virus and ways to prevent this.
Risk of Zika virus sexual transmission
While Zika is usually an asymptomatic or mild illness for the majority of people, it presents the greatest risk to the developing fetus. It is therefore imperative that women who are pregnant take enhanced measures to avoid exposure to Zika virus, including during sexual contact.
Women who are planning a pregnancy or are of child-bearing age and who may be exposed to Zika virus (either through travel or from their sexual partner), should also take enhanced precautions to prevent pregnancy and exposure to the virus during the specified risk periods (see below).
Recommendations for prevention
Public Health England (PHE) continues to review the current evidence for sexual transmission of Zika virus, and notes the recent development in advice from the WHO which is highly precautionary.
Based on all the available information to date and in line with other international guidance, including from the European Centre for Disease Prevention and Control (ECDC), PHE advises the following risk and evidence-based measures for individuals who may have been exposed to Zika virus (defined as either travellers returning from an area with high or moderate Zika virus risk or individuals who have had unprotected sexual contact with a potentially infectious partner).
Individuals with further concerns regarding potential sexual transmission of Zika virus and options for contraception should contact their GP for advice.
Barrier method options recommended for preventing Zika virus transmission include male or female condoms for penetrative sex (including sex toys) and male or female condoms or dental dams for oral-genital or oral-anal sexual contact. Sex toys should not be shared. To increase their effectiveness barrier methods should be used consistently and correctly, for the entire duration of sexual contact.
Advice on preventing sexual transmission of Zika virus is precautionary and is constantly under review as more information becomes available.
Individuals at greatest Zika virus risk
Pregnant women and their sexual partners
If either or both sexual partners have travelled to an area with high or moderate Zika virus risk, consistent use of barrier methods is advised during vaginal, anal and oral sex to reduce the risk of the developing fetus being exposed to the virus.
If both or just the male sexual partner travelled, these methods should be used for the duration of the pregnancy and should begin during travel and continue after return from an area with high or moderate Zika virus risk.
If the pregnant woman is the only traveller, barrier methods should be used for 8 weeks.
Couples should use barrier methods even in the absence of Zika symptoms.
Women planning pregnancy or of child-bearing age and their sexual partners
As Zika virus infection can have a severe effect on the developing fetus, pregnancy should be prevented using the most effective contraceptive measures during the period of potential exposure to Zika virus. If either or both sexual partners have travelled to an area with high or moderate Zika virus risk, conception should be prevented while travelling and after return.
In addition, transmission of Zika virus infection between sexual partners can be prevented by using barrier methods during vaginal, anal and oral sex.
As the risk period for Zika transmission is dependent on gender, the recommended time periods for application of contraceptive and barrier methods differs for men and women.
To reduce the risk of conception and being exposed to the virus, effective contraceptive and barrier methods should be consistently used whilst travelling and:
- female traveller only, symptomatic or asymptomatic – for 8 weeks after symptom onset or after last possible Zika virus exposure
- male traveller only, symptomatic or asymptomatic – for 6 months (an extended period as Zika virus survives in semen longer than other body fluids) after symptom onset or after last possible Zika virus exposure
If the couple is planning a pregnancy, both partners should be advised that attempts to conceive can resume after their specified time period.
All other individuals
Transmission of Zika virus infection between sexual partners can be prevented by using barrier methods during vaginal, anal and oral sex. The consistent use of barrier methods during sexual contact should begin while travelling to high or moderate Zika risk countries and continue for the period of time specified below depending on gender.
Male with or without symptoms
Female with or without symptoms
Last possible Zika virus exposure
Last possible Zika virus exposure is defined as the date of leaving an area with high or moderate Zika virus risk, or the date on which unprotected sexual contact with a potentially infectious partner took place.
Zika virus sexual transmission
Most Zika virus infections are transmitted via Aedes mosquitoes, however, a relatively small number of cases of sexual transmission of Zika virus have been reported. The vast majority of cases have involved men who experienced typical Zika symptoms at or before the estimated time of sexual transmission to their female partners.
There is only one published report of transmission by a man who had travelled to an area with active Zika virus transmission but never experienced Zika symptoms. Transmission of Zika virus from a female to a male sexual partner, and from a male to a male sexual partner has also been reported but these appear to be very rare events.
Zika virus in the genital tract
Zika virus has been shown to be present in semen, although it is not yet known how long this can persist, or whether the duration of virus persistence is longer in men who experience Zika symptoms. There has been one report of Zika virus RNA being detected (by PCR) in the female genital tract but it is not yet known how long this can persist.
Advice on fertility treatment or gamete donation
Published: 26 January 2016
Updated: 23 November 2016
- Revised advice on the duration of precautions to prevent sexual transmission.
- Revision, update and clarification
- Added additional advice regarding deferral of pregnancy in recommendations for prevention.
- Clarification of modes of sexual transmission
- First published.