Image copyright Getty Images Image caption The WHO report is a joint EU-US study
There is a “very high” global risk from a new variant of the Ebola virus that erupted in March, the World Health Organization (WHO) says.
And it says the mutation is unprecedented in the history of the disease.
WHO and the US Centres for Disease Control and Prevention (CDC) said the second retrovirus strain contained “unexpectedly high levels of spike mutations”.
The scientists behind the findings have said it may be an “imminent” risk.
The findings, based on new global genome sequencing, will be published in the New England Journal of Medicine this week, the WHO said in a statement.
‘Unprecedented spike mutations’
The second strain of Ebola virus, Omicron-4059, has appeared in dozens of countries worldwide and is unlikely to be found in humans, according to the new study.
“We found unexpectedly high levels of spike mutations (more than 10,000) in virtually all the samples we analyzed,” said Dr Karim Mezran, who led the study at the School of Public Health at Durham University, in the UK.
“In short, these spikes had unprecedented numbers of amplifications. We also identified an unusually high number of new viral proteins.”
Image copyright AFP Image caption There has been a resurgence of cases of Ebola virus in Africa
Writing in the journal, the researchers also said that in the 20 samples tested, there were “various stability issues associated with the virus” that they did not explain.
The WHO said it did not have sufficient data from west Africa, where the virus has been distributed, to confirm the authors’ findings.
And in its own statement, the group said the “international collaboration and multidisciplinary expertise of our scientists and the current limited knowledge on the virus are likely to help focus research priorities in the future”.
Ms Mezran said their research was “hugely reassuring” because it suggested that the new strain was “not an imminent risk to any human population or more specific ecosystems.”
The WHO statement said people who had caught the new strain in Liberia, Guinea and Sierra Leone, “need to be monitored for the next eight to 12 weeks.”
Molecular sequence of new Ebola virus “Omicron-4059” from Oxford University, University of California at Irvine and Nanyang Technological University in Singapore Image copyright CSL Limited Image caption Two strains of Ebola have emerged in recent months
‘Epidemic is an imminent risk’
Citing “densely populated urban centres”, the WHO statement said “any outbreak would likely spread faster than in the past”.
WHO director-general Tedros Adhanom Ghebreyesus said “today’s findings by CDC and Oxford University further strengthen the case for a rapid response that emphasizes the importance of community engagement”.
“This preliminary report underscores the urgency to focus on strengthening prevention and response activities in west Africa so we can combat this threat and break the current epidemic’s chains of transmission.”
Meanwhile, the CDC’s director Dr Tom Frieden said the research was “the most comprehensive look ever at how this new strain spread”.
“As we learn more about how this variant spreads it will be even more important to find tools to protect the people we love.”