NEW YORK -- Health officials now think Ebola survivors can spread the disease through unprotected sex nearly twice as long as previously believed.

Scientists thought the Ebola virus could remain in semen for about three months. But a recent case in West Africa suggests infection through sex can happen more than five months later.

Based on the case, officials are now telling male Ebola survivors to avoid unprotected sex indefinitely. They had previously advised using condoms for at least three months.

A report Friday detailed the case of a Liberian woman whose infection likely came from a man who had Ebola symptoms last September. She fell ill in March, a week after sex with him. She died. Another woman he had sex with around the same time tested negative.