New research has revealed that Ebola virus survivors can relapse and trigger outbreaks at least five years after infection.
This information came about through the analysis of an outbreak this year in Guinea, which was published in the Nature journal, according to Punch.
The outcome of the analysis was that “virus reservoirs” were found and they appear able to awaken and cause new infections and transmission for years.
Although scientists who monitored the virus in times past knew that the virus could actually lie dormant in survivors who test negative, this is due to the presence of the virus in the tissue rather than circulating in the blood. However, this new research has found that long-term follow-up of former patients is needed to prevent devastating flare-ups.
In an effort to trace the source of the outbreak in Guinea, the investigation involved 16 confirmed cases, 12 of whom died, researchers analysed the genomes of samples from several patients.
The analysis showed the Guinea strain was virtually identical to that from a 2013-16 wave, despite that ebola outbreaks are thought to result from the virus “spilling” from an animal host to a human.
Therefore, it is expected that it would have accumulated a certain number of mutations as it spread if the virus had been circulating actively in the community since then.
However, the 2021 virus had just 12 mutations, which has been said to be far fewer than would be expected during six years of sustained human-to-human transmission.
In essence, Alpha Keita, a researcher at the University of Montpellier who led the study suggested that the source was a reactivated virus that had lain dormant in a survivor.
According to Keita, “This is the longest known time between the declared end of an epidemic and a viral resurgence.
“It’s a new paradigm: the possibility that transmission from an individual infected during a previous epidemic could be the source of a new outbreak.”
There are, however, still questions around how, what and why a dormant Ebola virus is triggered to awaken and make a person or people sick. though there are some tantalizing clues.
One reason for this is that sometimes a spike in Ebola antibodies can be detected in survivors at a given time, which is a sign that the body is responding to a resurgent virus.