The deadly Ebola virus might be sexually transmitted by survivors’ months after their recovery via unprotected sex, the U.S. Centers for Disease Control and Prevention warns. The discovery suggests men who survive the disease should always use a condom during sex.

"We have suspected that having sexual contact with survivors could be a potential way for people to become infected," Dr. Barbara Knust, an epidemiologist and Ebola expert at the CDC, told NPR. "Prior to this outbreak we did have messages given to male survivors to abstain from sex for three months, and they were provided condoms."

Health officials now warn Ebola survivors can spread the disease through unprotected sex nearly twice as long as previously thought. Scientists said earlier the Ebola virus could remain in semen for about three months.

However, infection through unprotected sex can happen more than five months later. A recent case in West Africa, the CDC warned in the Morbidity and Mortality Weekly Report issued Friday, indicated the Ebola virus can persist longer than anyone previously thought in the seminal fluid of men who have recovered.

A 44-year-old woman in Monrovia, Liberia, became infected with Ebola after having unprotected intercourse with a 46-year-old survivor March 7, five months after the man was discharged from a clinic. Meanwhile, another woman with whom he had sex during the same time period tested negative.

Based on the finding from the case in Liberia, the CDC issued its warning Friday that contact with semen from male Ebola survivors should be avoided until more information is known about the duration of the virus. “If male survivors have sex [oral, vaginal or anal], a condom should be used correctly and consistently every time until further information is known,” the CDC said in a statement.

Separately, a woman in the southeastern town of Macenta contracted Ebola after having unprotected sex with her husband, the Associate Press reported. "We give a kit containing a condom" to all survivors leaving the treatment center, Dr. Sakoba Keita, the national coordinator for Ebola response in Guinea, told the AP