The Ebola epidemic, which has killed over 11,000 people to date, is the most devastating outbreak of the virus in history, killing more people than in every previous outbreak combined. Recently, the world welcomed the news that the three African nations at the center of the outbreak – Sierra Leone, Guinea and Liberia – had gone an entire week without recording a single newly diagnosed case of Ebola. However, a new study has confirmed that Ebola remains dormant in those that have stopped exhibiting symptoms of the disease. Specifically, the virus persists in the semen of male survivors far longer than previously thought.
The new study, published in the New England Journal of Medicine, discovered that two-thirds of the men investigated had detectable loads of the virus in their semen up to half a year after they had been initially infected; some even remained infectious up to nine months after contracting the disease. By analyzing the viral genetic codes in the male survivors’ semen, the researchers showed that many of them tested positive for Ebola, despite being asymptomatic – not showing any symptoms of the disease.
This in effect means that Ebola, for a certain time even after symptoms have disappeared, is a sexually transmitted disease. With a large number of Ebola survivors in West Africa, this new information will undoubtedly increase calls for male survivors to wear condoms for a prolonged period of time, perhaps indefinitely.
Although the case of a man who passed on Ebola to his sexual partner while he was asymptomatic was already reported earlier this year, this new study definitively confirms that the virus can be transmitted sexually even after the person is apparently cured of the disease.
The WHO has repeatedly advised constant vigilance and caution, determined to terminate any new outbreaks of the disease as they appear, and this new research will no doubt strengthen their resolve.
The research still leaves some doubt, however. The WHO notes that the sexual transmission of the virus is possible, but rare. Margaret Chan, the director general of the WHO, stated that she could not be sure that semen testing positive for the virus would actually still be infectious.
"The degree of uncertainty is worrying, that's why we need to take precautionary measures, so we advise survivors to take protection through contraception,” she told BBC News.