New research has uncovered that the ongoing Ebola outbreak in Guinea was most likely sparked by someone infected during the outbreak seven years ago. Viruses from both outbreaks are almost genetically identical, hinting that the virus did not jump from an animal to people, as scientists expected, but that it had lurked hidden in a human body for years.
As of March 6, 18 cases and 9 deaths had been reported in Guinea, according to Africa Centre for Disease Control and Prevention and 1600 vaccinated. Genetic analysis found that four viruses from people infected in the Guinea Ebola outbreak were the close relatives of viruses that had infected people in 2014.
Following the 2013-2016 outbreak, scientists discovered the virus could remain for extended periods of time in certain “immune privileged” sites in the body including the spinal cord, the brain, the eyes, placenta, and the testes, and can infect others on rare occasions. This transmission is most likely to occur via sexual contact with an infected person, as researchers hypothesize might be the origin of the latest outbreak
“This is pretty shocking,” virologist Angela Rasmussen of Georgetown University told Science magazine. “Ebolaviruses aren’t herpesviruses (which are known to cause long-lasting infections) and generally RNA viruses don’t just hang around not replicating at all.” Up to now the longest the virus has remained dormant in the body and subsequently cause a new infection was 500 days, said Miles Carroll, a virologist and professor at Oxford University who conducted the world’s largest study of Ebola survivors, which last year concluded immunity from the virus could last many years after infection.
“To have a new outbreak start from latent infection five years after the end of an epidemic is scary and new,” Eric Delaporte, an infectious disease physician at the University of Montpellier, told Science magazine. The initial data involved researchers from the Guinea health ministry, Senegal’s Pasteur Institute, the University of Edinburgh, the University of Nebraska Medical Center and the company PraesensBio
