Men and women returning from an area where Zika is spreading should refrain from sex or use condoms for eight weeks as a preventive step to stop the spread of the virus, according to updated guidance form the World Health Organization.
That is twice the amount of time the WHO recommended back in February, when the group said four weeks is enough to prevent sexual transmission of the virus.
The WHO also said any male showing symptoms of Zika infection, which include a rash and fever, should wait six months before having sex. So far, all published cases of sexual transmission of the virus have been from an infected male, and it remains unknown if women or asymptomatic men can transmit the virus via sexual transmission, the group said.
Despite those recommendations, the exact incubation time for the Zika virus, spread primarily by mosquito bites, is still unknown. The WHO said that it isn’t known how long the virus can remain in semen after symptoms occur.
Another wrinkle is that only one in five people infected with Zika show symptoms.
While Zika only causes a mild illness, federal scientists have confirmed a link between the virus and the birth defect microcephaly.
There are more than 500 cases of Zika in the continental U.S., but a large majority of the cases are travelers who got the virus in a country where it is spreading via mosquitoes. So far, mosquitoes aren’t spreading the virus in the continental U.S., although many fear that could happen next as it gets warmer.
