BACKGROUND
Ebola virus has been detected in the semen of men after their recovery from Ebola
virus disease (EVD). We report the presence of Ebola virus RNA in semen in a cohort
of survivors of EVD in Sierra Leone.
METHODS
We enrolled a convenience sample of 220 adult male survivors of EVD in Sierra Leone,
at various times after discharge from an Ebola treatment unit (ETU), in two phases
(100 participants were in phase 1, and 120 in phase 2). Semen specimens obtained at
baseline were tested by means of a quantitative reverse-transcriptase–polymerasechain-reaction (RT-PCR) assay with the use of the target sequences of NP and VP40 (in
phase 1) or NP and GP (in phase 2). This study did not evaluate directly the risk of
sexual transmission of EVD.
RESULTS
Of 210 participants who provided an initial semen specimen for analysis, 57 (27%) had
positive results on quantitative RT-PCR. Ebola virus RNA was detected in the semen of
all 7 men with a specimen obtained within 3 months after ETU discharge, in 26 of 42
(62%) with a specimen obtained at 4 to 6 months, in 15 of 60 (25%) with a specimen
obtained at 7 to 9 months, in 4 of 26 (15%) with a specimen obtained at 10 to 12
months, in 4 of 38 (11%) with a specimen obtained at 13 to 15 months, in 1 of 25 (4%)
with a specimen obtained at 16 to 18 months, and in no men with a specimen obtained
at 19 months or later. Among the 46 participants with a positive result in phase 1, the
median baseline cycle-threshold values (higher values indicate lower RNA values) for the
NP and VP40 targets were lower within 3 months after ETU discharge (32.4 and 31.3,
respectively; in 7 men) than at 4 to 6 months (34.3 and 33.1; in 25), at 7 to 9 months
(37.4 and 36.6; in 13), and at 10 to 12 months (37.7 and 36.9; in 1). In phase 2, a total
of 11 participants had positive results for NP and GP targets (samples obtained at 4.1 to
15.7 months after ETU discharge); cycle-threshold values ranged from 32.7 to 38.0 for
NP and from 31.1 to 37.7 for GP.
CONCLUSIONS
These data showed the long-term presence of Ebola virus RNA in semen and declining
persistence with increasing time after ETU discharge. (Funded by the World Health Organization and other