A Liberian woman appears to have contracted Ebola from unprotected sex with a man who survived the virus, health officials said today.
The 44-year-old woman was diagnosed March 20, the first new Ebola case in Liberia in a month. Doctors were perplexed by her case, because she hadn't been to a funeral or had any other contact with current patients, according to a report from the Centers for Disease Control and Prevention.
But the woman did have unprotected vaginal intercourse a few weeks earlier, with a 45-year-old Ebola survivor who has been free of the disease for months. The man developed the disease in September and was discharged from a treatment center in early October. That man also had sex with a second woman, who has not tested positive for Ebola, the CDC says.
Although doctors have known for some time that the Ebola virus can survive in semen long after a patient is considered cured, there has never been a clear, documented case of this happening, according to the CDC report.
People who survive Ebola — and whose blood tests show no sign of the virus — are generally considered to be non-infectious. The virus is spread through contact with bodily fluids and typically spreads through blood, a fact that has put health workers at very high risk of Ebola. People cannot spread the virus through casual contact, such as working in the same office or riding the bus. Ebola does not spread through the air.
But studies conducted during previous outbreaks have found that the Ebola virus can be found in semen up to 82 days after a patient's initial symptoms. Scientists don't know if the man's semen contains live Ebola viruses, although they plan to conduct such tests, the CDC report says.
Tests of the man's semen did find genetic material from the Ebola virus, called RNA. The tests were performed 199 days — or about 6½ months — after he first developed symptoms, suggesting that the genetic material can remain in semen much longer than previously known. Earlier studies have found genetic material from Ebola up to 101 days after the beginning of symptoms, the CDC says.
The CDC notes only one previous case of a possible sexual transmission of Ebola, although the new report describes the evidence as "inconclusive." Researchers also documented a possible case in which someone contracted the Marburg virus — which is similar to Ebola — in 1968.
The CDC has long warned Ebola survivors to either abstain from sex for three months or to use condoms during that time. Now, the CDC advises people to avoid contact with semen from male survivors. Men who survive Ebola should use condoms if they have sex and take care when disposing of the condoms.
According to the World Health Organization, 26,298 people have been infected with Ebola in the West African outbreak, and 10,892 have died, mostly in Liberia, Guinea and Sierra Leone.
Liberia has had no new Ebola cases in five weeks. That country's last confirmed case died March 27. The WHO declares countries to be Ebola-free 42 days after the last known case. If there are no additional cases, Liberia could be declared Ebola-free May 9.
A total of 33 new cases were diagnosed in Sierra Leone and Guinea in the week ending April 26, the WHO says. No health workers have been diagnosed with Ebola for the past two weeks. More than 865 health workers have been infected with the virus and 504 have died.
Guinea and Sierra Leone are still struggling to control risky practices that can spread Ebola, such as traditional burials in which mourners touch the dead. According to the WHO, 66 unsafe burials were held in Guinea the week that ended April 26.
During the same week, eight Ebola victims in Guinea were diagnosed only after death. That's a dangerous trend, because people who remain at home during their illness can spread the virus to many other people. Doctors have tried to isolate Ebola patients in treatment centers, both to keep them from transmitting the virus, as well as to provide the best chance of survival.
In related news, a patient admitted to a hospital in Charlotte, N.C., has tested negative for Ebola. The patient had been isolated at Carolinas Medical Center because of Ebola-like symptoms and recent travel to West Africa.