Possible sexual transmission of Ebola

ECDC comment

​The likelihood of sexual transmission of Ebola by person who recovered from Ebola virus disease is unknown. The World Health Organization recommends that "Ebola survivors should consider correct and consistent use of condoms for all sexual acts beyond three months until more information is available".

​On 1 May 2015, a report about the possible sexual transmission of Ebola virus in Liberia was published in the US Centers for Disease Control's (CDC) Morbidity and Mortality Weekly Report (1).

The article provides details of an investigation of a Liberian woman who was confirmed with Ebola virus disease on 20 March 2015. She had unprotected sexual contact with an Ebola survivor on March 7, 2015, seven days before onset of her symptoms. The survivor had onset of symptoms consistent with Ebola on 9 September 2014. Although the test in September 2014 was indeterminate (i.e. one assay indicating low viral load and a second assay showing negative results), the survivor showed a positive IgG result on 23 March 2015 indicating previous Ebola virus infection.

On 23 March 2015, his blood tested negative by RT-PCR and his semen tested positive by PCR, but with a low level of detectable viral nucleic acid.  A partial sequence from the survivor closely matched the sequence from the patient. The survivor’s semen was positive 199 days after onset of symptoms.

Ebola virus is known to be found in semen following recovery from the disease. Live virus have been isolated in semen of convalescent men 82 days after onset of symptoms and viral RNA has been detected by RT-PCR in semen of one patient up to day 101 after onset of symptoms. Yet, the likelihood of sexual transmission of Ebola by person who recovered from Ebola virus disease is not known.

The report published on 1 May indicates that the Ebola virus can persist in seminal fluid of a person who recovered from Ebola virus disease for longer than previously known and can potentially lead to sexual transmission of Ebola virus. As a consequence, the World Health Organization recommends that “for greater security and prevention of other sexually transmitted infections, Ebola survivors should consider correct and consistent use of condoms for all sexual acts beyond three months until more information is available” (2).

  1. Athalia Christie et al. Possible Sexual Transmission of Ebola Virus — Liberia, 2015.  MMWR, 2015, 64. http://www.cdc.gov/mmwr/pdf/wk/mm64e0501.pdf
  2. WHO, Sexual transmission of the Ebola Virus : evidence and knowledge gaps, 2015, http://www.who.int/reproductivehealth/topics/rtis/ebola-virus-semen/en/