Ebola could persist in semen for much longer than previously thought

A new longitudinal study suggests that the window during which male survivors of Ebola may be able to infect sexual partners is longer than was previously thought. Of a sample of 267 survivors in Liberia, 30 percent had Ebola virus RNA in their semen in at least one test, with at least one positive test result 40 months after infection. The previous record had been nearly eight months shorter. However, it’s not known how frequently viral RNA signals the presence of infectious virus. Nearly half the men also had a positive test after two negative tests. “That was … a surprise to all of us,” says Cavan Reilly, one of the study’s authors, because the WHO currently says that a person can be considered Ebola-free if semen is tested every three months until two consecutive tests are negative. Given this, the authors also suggest that the WHO’s recommendation may need to be reevaluated.