Sexual transmission may occur even in men with no symptoms of the infection. Previously it was recommended that men who have travelled to zika areas abstain or use condoms for 6 months to avoid infecting their partners. This was based on finding virus material in semen for more than 3 months in some cases. Newer information shows that live virus stops being in semen by one month usually. The new recommendation is: that men with possible Zika virus exposure who are planning to conceive with their partner wait at least 3 months after symptom onset or their last possible Zika virus exposure before engaging in unprotected sex. This applies to all sexual partners even those not planning pregnancy.
To check the latest information about risk countries see: www.who.int/emergencies/zika-virus/classification-tables/en/