Preliminary findings from an ongoing screening program in Liberia showed that Ebola virus RNA persisted in the semen of some survivors for 1 year or more, including one case where it showed up after 565 days.
The Men’s Health Screening Program (MHSP) also showed a marked increase in men reporting condom use or abstinence.
“This program provides important insights into how long Ebola remains in semen, a key component to preventing flare-ups of the disease and protecting survivors and their loved ones,” CDC Director Thomas R. Frieden, MD, MPH, said in a news release about the findings, which were published in The Lancet Global Health. “It also shows how investments in public health capacity can save lives.”
Results show longer persistence
The MHSP is operated in three locations by the Liberian Ministry of Health, CDC, WHO and Academic Consortium Combating Ebola in Liberia.
In addition to monthly testing services for male Ebola survivors aged 15 years and older, the program provides counseling and education about safe sex practices, including offering free condoms at every visit. The services are provided until a participant has two consecutive negative tests, at which time he graduates from the program.
Thomas R. Frieden
Semen samples are tested for Ebola virus RNA by real-time RT-PCR.
Between July 7, 2015, and May 6, 2016, 9% of the 429 patients for whom results were available had at least one positive test for Ebola in their semen. Among them, 63% had Ebola in their semen for at least 1 year after recovery, including the man whose semen tested positive 565 days after he was released from an Ebola treatment unit.
Further, men aged 40 years or older were likelier to have a semen sample test positive after 90 days than men who were younger.
The persistence of Ebola virus in semen has raised concerns about a resurgence of the disease, which killed more than 11,300 people during the West African outbreak, including more than 4,810 in Liberia, according to the CDC. Previously, it was shown to persist for up to 9 months, and flare-ups have included cases of sexual transmission.
In the Liberia study, 74% of survivors who reported having sex without a condom during enrollment in the program later reported using them at their first follow-up visit, and 46% of the patients who reported being sexually active at enrollment later reported being abstinent.
“Before this outbreak, scientists believed that Ebola virus would be found in semen for 3 months after recovery. With this study, we now know that virus may persist for a year or longer,” Moses J. Soka, MD, MHSP director, said in the release.
“We now have many more Ebola survivors than ever before. This work demonstrates the importance of providing laboratory testing and behavioral counseling to empower survivors to make informed decisions to protect their intimate partners.”
Caution urged in interpreting findings
Positive RT-PCR results cannot distinguish between the presence of infectious virus and residual virus RNA, cautioned Daniel G. Bausch, MD, MPH, associate professor in the department of tropical medicine at Tulane University School of Public Health and Tropical Medicine, and Ian Crozier, MD, of the infectious diseases institute at Kampala, Uganda, in a related commentary.
“Although concerning with regard to risk of sexual transmission during recovery from Ebola virus disease, the results must be interpreted with caution since, as with most other studies of Ebola virus persistence, confirmatory virus isolation on cell culture was not done,” they wrote. “This technique requires access to a biosafety level four laboratory, of which none exist in West Africa, and the logistical and regulatory obstacles of shipping samples internationally to suitable laboratories are formidable.”
Bausch and Crozier, who is an Ebola survivor, said outcomes of the risk-reduction efforts of the MHSP were as important as the test results.
“These behavioral changes might have not only prevented sexual transmission of Ebola virus and potential re-ignition of the outbreak, but also other sexually transmitted diseases and unwanted pregnancies,” they wrote. – by Gerard Gallagher
Disclosure: Frieden is the director of the CDC. Soka is director of the MSPH program and a coordinator of Ebola virus disease survivor clinical care at the Liberian Ministry of Health. The researchers report no relevant financial disclosures. Bausch and Crozier report no relevant financial disclosures.