The first likely case of sexual transmission of the Zika virus in the UK has been reported by the authorities.
The woman has made a full recovery, and it is thought she had been infected by her partner, who had recently visited a Zika-hit country.
Mostly spread by mosquitoes, Zika can linger in semen for months.
Cases of sexual spread have been reported in other countries and experts said the UK case was “not unexpected”.
An update by Public Health England said there had been 265 cases of Zika in the UK with one “likely” spread through sex.
Seven cases were in pregnant women.
While Zika is normally a mild infection, it can damage the development of a baby’s brain, leading to microcephaly.
Prof Dilys Morgan, the Zika incident director at Public Health England, said: “PHE advises all male travellers regardless of symptoms to avoid conception and use condoms and other barrier methods during sexual activities for six months following return from a Zika high- or moderate-risk country.”
Earlier this month the World Health Organization said Zika virus will no longer be treated as an international medical emergency. By lifting its nine-month-old declaration, the health agency acknowledged that Zika was here to stay.
Prof Jimmy Whitworth, from the London School of Hygiene and Tropical Medicine, said: “News that one case of sexual transmission of Zika has occurred in the UK is not unexpected.
“About 60 cases of sexual transmission of Zika have been reported worldwide, so we think this is quite rare.
“Discovering just how common it is for the virus to be passed during sex by a man or woman is a key focus for Zika researchers.
“Public Health England’s updated advice is also welcome.
“Zika virus survives in semen longer than other body fluids so recommending male travellers returning from Zika transmission countries, with or without symptoms, practise safe sex for six months is sensible.”