Saturday, December 4

Ebola virus hides in some survivors and may start outbreaks years later | Science


The deadly Ebola virus can hide in some survivors and reactivate even five years later, according to analysis of an enigmatic outbreak detected in early 2021 in Guinea, a country previously considered free of the disease since 2016. The discovery forces a redesign strategy against this microscopic killer, a 0.001 millimeter long organism that has so far killed every second infected. The two largest outbreaks in history, recorded in the last decade in West Africa and the Democratic Republic of the Congo, killed about 13,000 people, but there are more than 18,000 survivors. “This means that the risk of reappearance is greater than ever,” he warned in the magazine Nature an international team of scientists, led by the Guinean doctor Alpha Kabinet Keita.

The Spanish Anthropologist Almudena Marí Sáez has been one of the specialists who have spent two months in the Guinean city of Gouécké investigating the origin of the latest outbreak. Patient zero was a 51-year-old woman, a midwife at the local health center, who was admitted on January 21 with a headache, nausea and cramps. In an Ebola-free country, doctors did not suspect the virus and the woman was diagnosed with malaria and salmonellosis. He died a few days later. And after her, the relatives who cared for her died: her mother and three of her brothers.

“Ebola is the disease of love, because only the people you love are contaminated. If a person is sick, with diarrhea on top, it will be his partner, his mother or whoever lives with her who will wash him and become contaminated. And the same with vomiting and bleeding. It is a close and affective contact ”, explains Marí Sáez, from Instituto Robert Koch, In Berlin. The anthropologist makes a call not to stigmatize people who have overcome the disease. Ebola survivors are not time bombs capable of triggering an epidemic after taking the subway in any city in the world. At the moment, the cases of reactivation seem “relatively rare” and, furthermore, the virus is not so easily transmitted.

The Spanish anthropologist Almudena Marí Sáez, during a fieldwork, in April.
The Spanish anthropologist Almudena Marí Sáez, during a fieldwork, in April.Personal collection

Ebola was first detected in 1976 near the Ebola River in the Democratic Republic of the Congo and has caused at least 30 outbreaks since then. The largest of all began in Guinea in December 2013 and spread rapidly through Liberia and Sierra Leone, with isolated cases even in Spain, where nursing assistant Teresa Romero became infected after caring for two sick missionaries repatriated from West Africa. The virus killed 11,000 people and apparently vanished in June 2016, leaving about 17,000 survivors. Genetic analyzes now show that the variant detected this year, with very characteristic mutations, is the same as that of the previous large outbreak, which makes it “very unlikely” that its origin is a recent jump from a bat, an ape or another. animal reservoir of the virus.

The team of the Spanish anthropologist has interviewed the relatives and companions of the deceased midwife, to try to find out how she was infected. There is no evidence that the woman suffered from Ebola in the 2013-2016 outbreak, although scientists do not rule out that she had a mild infection, without realizing it. The virus then killed 20 of his distant relatives. Another possibility is that he was infected this year in his health center, when he came into contact with the bodily fluids of a survivor with the reactivated virus. And the third hypothesis is sexual transmission, through the semen of a survivor, although there is no evidence that her husband — polygamous, with another wife and a lover — was infected in the previous epidemic. There is still no solution to the riddle.

Scientists propose “continuous surveillance” of the more than 18,000 Ebola survivors, without stigmatizing them

When Ebola appeared in Guinea in 2013, the anthropologist Almudena Marí Sáez was already there investigating another hemorrhagic virus, the cause of Lassa fever. His team then tracked down the Ebola outbreak and argued that it could have been started by an infected child after playing with bats in a tree hole in Meliandou, a village in southern Guinea. Marí Sáez recalls that the survivors of that epidemic “suffered ostracism in their communities, they lost their jobs, people did not approach them, they had to go to bars with their own cup and they went to buy and they did not sell food”. The anthropologist fears “a re-stigmatization” of some people who “at the same time were seen as heroes”.

The virologist Rafael Delgado studies fragments of the Ebola virus in his laboratory at Hospital 12 de Octubre, in Madrid. The expert recalls that the February 2021 outbreak in the Democratic Republic of the Congo was already linked to possible sexual transmission of the virus by a survivor of the previous epidemic in the country, which ended in June 2020. “The new study in Guinea is a confirmation that was expected. The special thing now is the time: those five years ”, he points out.

Delgado affirms that it is already “absolutely clear” that the Ebola virus is capable of remaining in a latent state in “immune sanctuaries” of the human body, such as the testicles or the eye, safe from the body’s defenses for years. Official figures for the 2013-2016 outbreak speak of 28,000 infected, but Delgado believes they could be hundreds of thousands. “So far, as far as we know, [las reactivaciones de virus latentes] they are exceptional cases, but they can exist and must be taken into account ”, warns the virologist, who has not participated in the new study. In his opinion, the risk of the disease appearing in a country like Spain is “extraordinarily low”.

“They are exceptional cases, but they may exist and must be taken into account”, warns virologist Rafael Delgado

Delgado also recalls that there are already two Ebola vaccines, manufactured by Merck and Janssen, and some relatively effective treatments, such as the Inmazeb, from the American company Regeneron. “Surely it is convenient to carry out an extensive vaccination campaign to prevent the virus from circulating again in areas where there has been very active transmission,” says the researcher.

Alpha Kabinet Keita, MD, Deputy Director of the Center for Research and Training in Infectious Diseases of Guinea, and his team consider that “continuous surveillance of Ebola survivors is justified” to avoid possible relapses. The anthropologist Almudena Marí Sáez insists that the stigmatization of the victims must be avoided in any way. Spanish survivor Teresa Romero described in 2017 the ordeal she suffered three years earlier. “I felt that death was stalking me, an entity leaning on my shoulder was waiting for me calmly. Something that cannot be explained in words. Even today I don’t know how I could get out of there ”, said the assistant in the magazine Clinical Nursing. “No one can imagine what I went through in October 2014, except the Ebola survivors.”

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