This is a completely new observation. Analysis of the genome of the Ebolavirus, responsible for an epidemic outbreak in Guinea since last February, shows that it is almost identical to that of the 2013-2016 epidemic. The hypothesis? The virus would have remained hidden in the body of a survivor for at least 5 years.
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Since mid-February, Ebola disease is back in Guinea, about five years after the end of theepidemic from December 2013 to January 2016 which left around 2,500 victims in the country. The 2021 epidemic has its roots in the Gouécké sub-prefecture, probably between January 18 and February 13. The triggering event appears to be the burial, without sanitary measures, of a 51-year-old nurse on 1is February 2021. Several members of her family, as well as a doctor whom she had consulted, developed symptoms Ebola disease like diarrhea, vomiting and bleeding. Of these people, four died and two were placed in quarantine.
The 51-year-old nurse would therefore be the patient 0 of this epidemic outbreak. Sick since January 18, she was first diagnosed with fever thyphoid, then for the malaria before his death on January 28. According to the latest WHO report On the situation, 192 contact cases were identified in the Gouécké region and in a health center in Conakry. As with every epidemic, scientists identify the strain of Ebola virus (Characteristics of Ebolavirus
Ebola virus, from the Filoviridae family, has four subtypes:
Zaire; Sudan; Ivory Coast; Reston.
Three of the virus subtypes, … “data-image =” https://cdn.futura-sciences.com/buildsv6/images/midioriginal/4/7/8/4781da9d9f_50034659_ebola-dr-01.jpg “data- url = “https://www.futura-sciences.com/sante/definitions/medecine-virus-ebola-4218/” data-more = “Read more”>EBOV) who is responsible for it. Except this time, the result was totally unexpected!
The strain of 2014 very close to that of 2021
These analyzes, which have not yet appeared in peer-reviewed journals, are published on the site virological.org, a reference forum on the epidemiology and evolution of virus, where three teams published their findings on March 12. According to these analyzes, the current strain of EBOV belongs to the lineage Makona of the Species is the fundamental entity of classifications, which brings together living beings with a set of morphological, anatomical, … “data-url =” https://www.futura-sciences.com/planete / definitions / zoologie-espece-2261 / “data-more =” Read more “>species Zaire, just like the strain of the 2013-2016 epidemic. This means that the current epidemic would not be due to a zoonotic event, i.e. the contamination from human to animal, but the result of human-to-human contamination.
The Institut Pasteur in Dakar in Senegal received several samples of this strain for sequence them. It appears that it shares around ten mutations with that of 2014, including the A82V mutation which is an adaptation of EBOV to humans that appeared in 2014. Scientists expected to see much more divergence between the two virus, especially if it has been actively circulating in a human population. The virus evolution rate is 0.0012 substitution per site and per year; if the EBOV had circulated in the human population during the 5 to 7 years between the two epidemics, the EBOV of 2021 would have to carry approximately 110 substitutions. It is off the mark.
Ebola virus hidden for 5 years in the body of a survivor
The most likely hypothesis to explain these observations is that the 2014 EBOV remained latent in the body of an outbreak survivor for 5-7 years. This person would then have infected the nurse who died at the end of January. The persistence of EBOV has already been reported in a publication of 2016. The latter describes the case of a survivor of the 2013-2016 epidemic in whom the virus remained hidden for 500 days in his testicular function
The testes are glands that produce testosterone, the main male hormone responsible for the development of the genitals. Its production, at the onset of puberty, causes … “data-image =” https://cdn.futura-sciences.com/buildsv6/images/midioriginal/0/c/2/0c215ec3b0_50035153_anatomie-homme-bmf81- wikipedia-cc-by-sa-30.jpg “data-url =” https://www.futura-sciences.com/sante/definitions/biologie-testicule-6143/ “data-more =” Read more “>testicles. He then sexually transmitted the virus, causing a resurgence of the disease. The testes are special organs that have a ” immune privilege », That is to say that an agent pathogenic can hide there without triggering an inflammatory reaction. The Function of the Brain
Located in the cranial box, the brain is the seat of higher functions (cognitive functions, senses, nervous responses) and vegetative. It is therefore an essential organ which ensures the regulation of all … “data-image =” https://cdn.futura-sciences.com/buildsv6/images/midioriginal/5/c/b/5cb474dd85_121782_cerveau-3d .jpg “data-url =” https://www.futura-sciences.com/sante/definitions/biologie-cerveau-3125/ “data-more =” Read more “>brain, the eyes and the function of the uterus
The uterus is a pocket designed to accommodate an embryo and promote its development. The inner lining of the wall, called the endometrium, is sensitive to female sex hormones … “data-image =” https://cdn.futura-sciences.com/buildsv6/images/midioriginal/3/c/1/3c164e7680_50034599_uterus -dr.jpg “data-url =” https://www.futura-sciences.com/sante/definitions/biologie-uterus-3861/ “data-more =” Read more “>uterus during the pregnancy are also immunoprivileged organs.
Scientists assume this is the same scenario that unfolded in early 2021, but over a much longer time frame. The 51-year-old nurse was sexually infected with a survivor of the previous outbreak who kept the virus in her body for at least 5 years. These observations are a game-changer in understanding the onset of Ebola epidemics, but are the result of a scientific investigation still in progress and may therefore be called upon to change.
In addition, they involve a new challenge for Ebola survivors and their loved ones, but also caregivers. Indeed, survivors of the disease face a terrible stigma in their country and the assumption that they can transmit the disease, despite themselves, five later is likely to worsen their condition. WHO has sent around 11,000 doses of Ebola vaccine, manufactured by Merck, in Guinea at the end of February to curb the epidemic.
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