The World Health Organization (WHO) is conducting further investigations on the individual who appears to have had the virus latent in his body.
This suggests that infections may 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, have sequenced the genome of nine samples taken from infected people during the current outbreak and compared them with sequences from previous outbreaks to help identify the cause.
The results suggest that the most recent outbreak “is the result of the resurgence of a strain that previously circulated in the West African outbreak,” the authors wrote in their analysis.
“The similarities are big enough to state that this is the same family as the virus,” said Dr. Salam Gueye, director of the Emergency Preparedness and Response Group at the WHO Regional Office for Africa.
But Dr. Alpha Keita, deputy director of the Center for Recherche et de Formation en Infectiologie de Guinée (CERFIG) at the University of Conakry, who led the research, said his team refrained from jumping to conclusions.
They decided to be extremely careful and continue to sequence on additional samples to obtain more complete sequences that will provide a safer response, he added.
In a separate report on the work, Keita explained that the implications in terms of public health and people’s safety, such as the risks of stigmatization, physical and verbal violence among former Ebola workers, required such an approach.
Gueye said further investigations are underway to see what exactly happened.
Guinea’s Ministry of Health declared a new Ebola virus outbreak in the country’s Nzérékoré region on February 14. As of March 25, 18 cases have been reported, including 14 confirmed cases and four probable cases. Nine people died and 366 contacts are being followed up.
The latest outbreak began just 200 kilometers from the epicenter of the previous epidemic, according to the researchers.
A sexually transmitted virus?
The nurse was the brother-in-law of the survivor’s wife, who reportedly has been carrying the virus for five years. The spouse later died of Ebola disease, the nurse soon developed the disease and is believed to have passed it on to others during the funeral. “This is how the outbreak may have started,” said Gueye.
Then, CERFIG teams sequenced the nine samples of people who tested positive for Ebola, with the Makana variant identified in these samples.
The virus may have been latent and subsequently sexually transmitted from one person to another, or the virus was present in the body and did not cause disease, but due to the virus mutation or decreased host immunity, it caused a relapse, Gueye told CNN .
“We continue to carry out epidemiological and anthropological investigations to reinforce this hypothesis or to exclude it, but so far this is the strongest hypothesis we have,” said Gueye.
Wim Van Damme, a researcher and specialist in infectious diseases at the Antwerp Institute of Tropical Medicine, who did not participate in the research, warns that this method of transmission 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 although many people think the infection was probably a case of sexual transmission. “This is not certain because the virus can remain present in other parts of 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 complementary investigations 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 react,” Gueye told CNN.
WHO is working with affected West African governments and a task force has been formed. “The task force will go further into epidemiology, bioinformatics and the laboratory to see what we can learn from this experience and translate it 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 testing for the virus. We can also provide condoms for them,” said Dr. Merawi Aragaw, Incident Manager for Ebola, CDC Africa.
“The community needs continuing education. We are trying to reach the community through health professionals that they can trust, ”said Aragaw, adding that Africa’s CDC provides psychological support to survivors and advises partners and people in the community.
WHO says it will strengthen surveillance, disease detection and disease responses for countries affected by Ebola.
“It will change the way we are responding to Ebola and the way we are preventing Ebola. It is a disease that needs to be in the surveillance system and needs the collaboration of the community, health professionals, and it also needs to be a priority for health authorities, “said Gueye.
Ebola virus disease (EVD) is a rare but serious disease, often fatal in humans. 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 suspected cases were reported along with 11,323 deaths.