The Ebola viruses behind a new outbreak in Guinea are surprisingly similar to viruses identified during the massive West African outbreak that stretched from 2013 to 2016, according to a new genetic analysis. The finding suggests that virus may have been kept in silence by a survivor for at least five years and that the current outbreak was instigated by that unfortunate person, rather than a spill from an animal reservoir.
In the genetic analysis published online on Friday, a group of international researchers reported that Ebola viruses collected during the current outbreak in Guinea have only a dozen genetic differences from Ebola variants collected in the same area in Guinea in 2014. is. Based on what researchers know about the rate at which Ebola accumulates such genetic substitutions – its rate of evolution – the number of accumulated differences should have been more than 110 in those time periods, not 12.
“This number of replacements is much less than would be expected during sustained human-to-human transmission,” researchers write in their analysis. Instead, they note that such a slow pace of evolution is a ‘feature of persistent infections’.
‘Therefore, the index case of the Guinea group in 2021 was probably contaminated from a persistent source, such as through sexual transmission of a [Ebola] survivor, ”they conclude.
The Ebola virus is known to persist in some survivors, especially in places where it can lie low off the immune system, such as the testicles or eyeballs. A study from 2016 reported more than 500 days after the initial infection the revival of the virus in the seminal fluid of a survivor.
The team of more than five years was still ‘shockingTo many virologists and public health experts. And it raises a variety of concerns for the many survivors of outbreaks in the past, some of whom have had mild cases of Ebola without realizing it. In particular, many people who are known to have survived Ebola face stigma, and the possibility of years of perseverance is likely to exacerbate the problem.
In the outbreak of West Africa 2013-2016, more than 28,000 people were infected with the virus, and more than 11,000 died. This is the largest Ebola outbreak in history. Most cases and deaths were in Guinea, Liberia and Sierra Leone. The outbreak began with a case reported to an 18-month-old boy in December 2013; the boy is thought to have contracted the virus from bats.
The current outbreak, declared on February 14, has left at least 18 sick and nine dead. Vaccination efforts are now underway to stop the spread of the virus.