We have been slowly but surely winning the war against the Ebola outbreak, with countries across West Africa including Sierra Leone and Guinea drastically reducing the number of cases - partly thanks to a new trial vaccine. But there may still be a risk of another outbreak occurring, via male semen.

Earlier this year the World Health Organisation (WHO) warned that Ebola can remain infectious in semen for up to 82 days. This means that male survivors of Ebola are required to be tested three months after they first developed symptoms, to ensure there is no risk of them passing the virus on.

But new research has claimed that three months is not enough, and Ebola can actually survive for up to six months inside semen. "The old advice of three months is no longer good," an unnamed clinician familiar with the study told Reuters. "The number of people with persistent virus in their semen is much greater than expected."

The study, to be published in the New England Journal of Medicine, found that around half of 200 survivors monitored had traces of Ebola in their semen after six months. And they warned that there was a risk of the virus being passed on via sex, and also masturbation. "It's the semen that is dangerous. How people actually get exposed, in soiled linens or whatever, is not clear," noted Bruce Aylward, head of the WHO’s Ebola response, in a news conference recently.

According to the research, there will continuously be a chance of flare-ups despite the outbreak almost being stamped out, and greater precautions will need to be taken. However, sexual transmission is not thought to be a huge problem, as it did not contribute much to the spread of Ebola when the outbreak began last year.

To reduce the chances of spreading the virus via semen, the WHO guidelines currently state that male survivors should maintain good personal hygiene after sex or masturbation and "if an Ebola survivor’s semen has not been tested, he should continue to practice safe sex for at least six months after the onset of symptoms."

credit link: iflscience