LONDON Some male survivors of Ebola infection can harbor fragments of the virus in their semen for at least nine months after their initial infection – far longer than previously thought, scientists said on Wednesday.
In preliminary results which raise questions about how and when the West African epidemic can be brought to an end, researchers said they do not yet know whether the traces of virus found were live or potentially infectious.
“These results come at a critically important time – reminding us that while Ebola case numbers continue to plummet, Ebola survivors and their families continue to struggle with the effects of the disease,” said Bruce Aylward, a World Health Organization (WHO) Ebola expert.
He said survivors, of whom there are up to 17,000 in West Africa, needed “continued, substantial support for the next six to 12 months to meet these challenges and to ensure their partners are not exposed to potential virus”.
Ebola infected 28,000 people and killed more than 11,300 in an outbreak centered on Guinea, Sierra Leone and Liberia which is just coming under control.
Disease experts say they are only now able to learn more about Ebola and its potential longer-term effects on survivors.
This study included 93 male Ebola survivors over the age of 18 from Freetown who gave semen samples for testing. The men enrolled in the study two to 10 months after their illness began.
All the men tested in the first three months after becoming ill were positive for Ebola virus. Some 65 percent tested four to six months after their illness were positive, while a quarter of those tested seven to nine months after falling ill tested positive.
“Why some study participants had cleared the fragments of Ebola virus from semen earlier than others remains unclear,” the researchers said in a statement about their results published in the New England Journal of Medicine on Wednesday.
It said further tests of the samples were being conducted by the U.S. Centers for Disease Control and Prevention “to determine if the virus is live and potentially infectious”.
The WHO’s advice is that all male survivors should be tested three months after the onset of symptoms and then monthly until they know they have no risk of passing on the virus.
“Until a male Ebola survivor’s semen has twice tested negative, he should abstain from all types of sex or use condoms when engaging in sexual activity,” the WHO said. “Hands should be washed after any physical contact with semen.”
(Additional reporting by Stephanie Nebehay in Geneva; editing by Andrew Roche)