BRISBANE, AUSTRALIA – The first possible case of sexual transmission of the Ebola virus has been recorded in Liberia, Dr. Nicola Low reported at the World STI & HIV Congress 2015.
The woman diagnosed with the Ebola virus had no contact with any other Ebola patients, despite extensive contact tracing. The only possible source of the virus was sexual contact with a man who had been ill with the disease and recovered 6 months before he had contact with her.
Dr. Low, of the Institute of Social and Preventive Medicine at the University of Bern in Switzerland, said that while only a partial genetic sequence was available for the male Ebola survivor’s virus, the sequence was very similar to that of the virus taken from the infected woman.
“It cannot be definitively confirmed as sexual transmission, but it is highly suggestive,” Dr. Low told conference attendees.
Dr. Low showed data from a study of 100 male Ebola virus survivors, which demonstrated that the virus could persist in semen for up to 9 months after the first onset of symptoms.
“In the first 3 months after symptom onset, all men had Ebola virus detected in semen and even after 6 months, the majority still had Ebola virus detected in semen, so the persistence in semen seems to be far longer than we have previously suspected,” she said.
There is growing evidence of “immunologically privileged” sites, such as the gonads and eyes, where the virus can persist long after the disease itself has resolved, Dr. Low said.
The persistence and potential sexual transmission of the Ebola virus has implications for management of Ebola virus disease survivors, but also demands further research, Dr. Low said.
“We need this information because it needs to [inform] safe sex guidelines to tell people how to look after themselves and protect their partners during an Ebola epidemic,” she said. “The advice is that men who have had Ebola should be offered semen testing monthly until they have two negative reverse transcriptase PCR [tests], and if they have had no semen testing, they should avoid sex or have [only] safe sex for at least 6 months after onset of symptoms.”
Despite the presence of Ebola virus in semen, Dr. Low said the likelihood of sexual transmission appears to be low.
“Our assumption is that the viral load in semen is probably not very high, but we don’t know that for sure,” Dr. Low said in an interview. “If it’s not really very infectious, then it’s not going to cause very many cases.”
Dr. Low reported having no financial disclosures.