Scientists investigate whether the recent Ebola outbreak in West Africa came from a man who survived an epidemic five years ago

The World Health Organization (WHO) is conducting further research into the person with whom the virus appears to have been dormant in their body.

This would indicate that infections can persist once people recover and have the potential to start a future outbreak.

International researchers, including a team from the University of Conakry in Guinea, sequenced the genomes of nine samples taken from people infected during the current outbreak and compared them with sequences from previous outbreaks to help determine the cause .

The results suggest that the latest outbreak “is the result of the resurgence of a strain that previously circulated during the West African outbreak,” the authors wrote in their analysis.

The team found that the circulating Ebola virus strain resembled that of the Makano strain, which was responsible for the 2014-2016 widespread outbreak in West Africa.

“The similarities are significant enough to state that this is the same family of the virus,” said Dr. Salam Gueye, director of the Emergency Preparness and Response Cluster at the WHO Regional Office for Africa.

But Dr. Alpha Keita, deputy director of the Center de Recherche et de Formation and Infectiologie de Guinée (CERFIG) at the University of Conakry, who led the study, said his team did not jump to conclusions.

They decided to be extremely careful and to continue sequencing additional samples to obtain more complete sequences that will provide a safer answer, he added.

In a separate report on the work, Keita explained that the public health and safety implications, such as the risks of stigmatization, physical and verbal abuse among previous Ebola sirvivores, called for such an approach.

Gueye said further investigations are now underway to see what exactly happened.

Guinea’s Ministry of Health announced a new outbreak of Ebola virus disease in the Nzérékoré region of the country on February 14. As of March 25, 18 cases were reported, including 14 confirmed and four probable cases. Nine people died and 366 contacts are being followed up.

The latest outbreak started just 200 km from the epicenter of the previous epidemic, according to the researchers.

A sexually transmitted virus?

The first case of the current outbreak, identified in the sub-county of Gouécké, was a nurse who died in late January 2021. All other cases are people who attended the funeral on Feb. 1, 2021, Gueye said.

The nurse was an in-laws of the survivor’s husband who is believed to have carried the virus for five years. The husband subsequently died of Ebola virus disease, the nurse soon developed the disease and is said to have passed it on to other people during the funeral. “That’s how the outbreak may have started,” said Gueye.

Teams at CERFIG then sequenced the nine samples from people who tested positive for Ebola, identifying the Makana variant in these samples.

The virus may have been latent and then sexually transmitted from one person to another or the virus was present in the body and did not cause disease, but due to a virus mutation or declining immunity, it caused a relapse, Gueye told CNN.

Semen has been found to contain traces of the Ebola virus long after a person was declared disease-free.

“We’re going to continue with epidemiological and anthropological research to reinforce or rule out that hypothesis, but so far that’s the strongest hypothesis we have,” said Gueye.

Wim Van Damme, a researcher and expert in infectious diseases at the Institute of Tropical Medicine, Antwerp, who was not involved in the study, warns that this transmission method would be a very rare event. “There are more than 10,000 Ebola survivors in West Africa, and this is the first case after five years,” he said.

He added that while many people think the infection was most likely a case of sexual transmission. “That is not certain, because the virus can remain in other places in the body (mainly in the central nervous system).” But he explains that it is also not known how the virus would spread from the nervous system to another human being.

“We need to do additional research and epidemiological research to determine what happened and to have a strong hypothesis about it. There are many facts that have given us enough information to respond,” Gueye told CNN.

Health workers from the Guinean Ministry of Health are preparing forms to register medical personnel before receiving their anti-Ebola vaccines at N'zerekore Hospital.

The WHO is working with the governments affected by West Africa and a task force has been formed. “The task force will delve further into epidemiology, bioinformatics and laboratory to see what we can learn from this experience and translate this into the program,” said Gueye.

The risk of future outbreaks

“The fact is that we need to monitor these survivors for extended periods of time with frequent semen analysis of the virus. We can also provide condoms for them,” says Dr. Merawi Aragaw, Incident Manager for Ebola, Africa CDC.

“The community needs ongoing education. We try to reach the community through health professionals they can trust,” Aragaw said, adding that the Africa CDC provides survivors with ongoing psychological support and advises partners and people in the community.

The WHO says it will strengthen surveillance, disease detection and disease responses for countries affected by Ebola.

“It will change the way we respond to Ebola and the way we prevent Ebola. It is a disease that has to be in the surveillance system and it takes community, health professionals, and it has to work together. a priority for health authorities, ”said Gueye.

Ebola virus disease (EVD) is a rare but serious, often fatal, human disease. The virus usually spreads through direct contact with the blood, body fluids, or tissues of infected people or animals.

The 2014-2016 Ebola epidemic in West Africa was the largest to date, spreading to Liberia, Sierra Leone and Guinea.

A total of 28,646 suspicious cases were reported, along with 11,323 deaths.

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