Washington: The deadly Ebola virus can persist in the semen of survivors for more than two years after the onset of infection, a study has found.
Researchers at the University of North Carolina at Chapel Hill in the US also detected Ebola virus RNA in the semen of men who had previously had a negative test of their semen in some cases. These findings led the team to suggest revision of the 2016 World Health Organisation (WHO) guidelines relating to the sexual transmission of Ebola.
The guidelines call for men who survive Ebola virus disease (EVD) to undertake measures such as abstinence and the use of condoms for at least 12 months after the onset of EVD or until their semen has tested negative for Ebola virus RNA twice.
Of the 149 men who provided samples, 13 tested positive for Ebola virus RNA. Of these 13 men, 11 had positive results even two years after the onset of Ebola infection. "Our finding of long term persistence and intermittent detection of viral RNA in semen suggests we need to change how we think about Ebola as it is no longer only an acute illness, but also one with potential long-term effects," said
William A Fischer, an assistant professor at University of North Carolina at Chapel Hill. "It is becoming clear that in some survivors, evidence of the virus can linger in the male genital tract for long periods of time with important potential implications for transmission," said Fischer, co-author of the study published in the journal Open Forum Infectious Diseases.
He noted that while there has been documented sexual transmission of Ebola earlier after acute infection, it is not known whether the presence of RNA serves as a correlate for infectious virus and if transmission this far out is possible. The study team also reports that the men whose samples tested positive for Ebola virus RNA were more likely to be older than those with a negative result.
Those who had Ebola virus RNA detected in their semen also complained of vision problems at a higher rate than male survivors without evidence of Ebola virus RNA in their semen. The researchers recommend future studies investigate the source of viral persistence and whether the detection of viral RNA signifies the presence of infectious virus.
