An Indian man recovered from Ebola back in September, before flying from Liberia to Delhi on Nov. 10—but the 26-year-old has been quarantined anyway, because though his blood tested negative for the virus, his semen tested positive. Ebola lingers in semen for months after a person has recovered, a Doctors Without Borders coordinator explains to NPR, "because antibodies produced in the bloodstream don't reach the testicles." Male survivors are told to wear condoms for three months following their recovery; the CDC officially recommends they abstain from sex for three months. But India will keep this man quarantined until his semen tests negative, according to a statement from the country's Ministry of Health.
"This would rule out even the remote possibility of spread of this disease by the sexual route," says the statement. And though at least one virologist isn't aware of a case of Ebola being transmitted sexually, the Marburg virus, which is related to Ebola, was. In 1967, a German man was cured of Marburg and released from the hospital; four months later, he transmitted the virus to his wife. The 26-year-old in this case is India's first Ebola patient, Time reports. Though he has a medical clearance certificate that would deem him free of the virus in the eyes of WHO and the CDC, as the Times of India notes, the country is concerned it won't be able to handle an outbreak considering its population density, overburdened government health services, and low hygiene standards.