A few women have been infected with Zika by their sexual partners. The men have all passed the infection on either just before having the illness or during it or shortly after it. No cases have been seen from men who didn't have symptoms. Because the virus can remain in semen longer than it is in the blood stream it is advised that men abstain or use condoms for at least 6 months after Zika infection. Those who travel to Zika areas but who don't get any symptoms of the infection should abstain or use condoms for 8 weeks.