Dubai, United Arab Emirates (CNN) – The monkey line continues to spread to countries where the virus is not normally endemic, putting global health officials on high alert.
Currently, with more than 643 cases of monkey pox identified in dozens of countries where the virus is not endemic, Tedros Adhanom Ghebreyesus, Director-General of the World Health Organization, stated on Wednesday that “this sudden outbreak of monkey pox in “Many countries at the same time indicate that there may have been an undetected transmission of the infection for some time.”
The virus has been spreading to countries located in West and Central Africa for decades. In preliminary research published this week, scientists at the University of Edinburgh Institute for Evolutionary Biology describe how the genotype they see suggests that “there has been continuous human-to-human transmission since at least 2017”.
Genetic sequences in this research showed that the first cases of monkey pox in 2022 resulted from an outbreak of the virus that led to the outbreak of infections in Singapore, Israel, Nigeria and the UK, between 2017 and 2019.
“This spread of the virus has continued for a long time, locally,” said Michael Worubie, an evolutionary biologist and professor at the University of Arizona, who is not involved in the research. He added that this means that the world has failed to protect those living in areas with limited resources, where the disease is endemic, and to control it in its homeland, before it spreads globally.
“It’s really the story of a two-wave explosion,” Worubi explained, “noting that we actually need to turn our attention to where it is spreading … and pay attention to these populations, as much as we do.” “It’s interesting what is happening in every other country in the world.”
If research continues to show that the virus has spread more from humans than previously thought from animals to humans, according to Worubi, one of the “really good questions” is, why did the world not think that apes could be endemic in countries outside West and Central Africa?
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Epidemiologist Anne Remoen has studied the monkey line for nearly 20 years and has repeatedly warned that its spread to countries like the Democratic Republic of the Congo could have wider global health implications.
“If monkey pox becomes endemic to a wildlife community outside Africa, it will be difficult to reverse a change in public health,” warned Rimoin, a professor of epidemiology at the Fielding School of Public Health at UCLA, in an article 2010 in the Proceedings of the National Academy of Sciences.
The recent monkey pox outbreak is proving difficult to predict, in part because we have not been able to fully trace its origin.
“We do not even know when it started to spread,” Rimoen added. “It has probably spread quietly for some time.”
Previous human cases of monkey pox have not been seen beyond initial exposure to an infected animal, usually a rodent. Once the virus spreads among these animals, it can continue to be transmitted to humans.
Remoen told CNN that if we witnessed a steady transmission of the virus from one person to another, albeit at a low rate, it would suggest transmitting the infection back to animals in places not affected by a source “a existential threat to an opportunity. ” This fact allows the virus to survive in an environment and pass between animals and humans over time.
“We know a lot about this virus, but we do not know everything about it,” Rimoen noted, “so we’re going to have to study this reality very carefully.”
Too early to give reassurance
WHO officials have stated that the global risk to public health from this virus is moderate.
According to a risk assessment report released by the World Health Organization on Sunday, “public health risks can become high if the virus takes advantage of the opportunity to establish itself as a human pathogen and spreads among the most vulnerable groups to human diseases. severe, such as young children and people with weakened immune systems. ” “.
The organization urged “countries to take immediate action to reduce the spread of the virus among vulnerable groups and among the general population, and to avoid viewing monkey pox as a clinical condition and a public health problem in currently non-endemic countries.” .
During a news conference last week, a U.S. Centers for Disease Control (CDC) official said it was “too early to say” if the virus could become endemic in the United States, but experts were still “hopeful.” “that will not t.
“I think we are still in the early days of our investigation,” said Dr. Jennifer McQuiston, Deputy Director of the Division of Pathogenesis and Pathology at CDC.
McQuiston noted that the virus was not endemic after the last outbreak of monkey pox in the United States in 2003, when slaughtered dogs transmitted the virus to dozens of people in several states.
“Hopefully we can contain it as before,” she added.
The European Center for Disease Control agreed with its assessment with McCuston last week, noting that there was no evidence that the virus had been placed in the wild in the US after authorities launched an “aggressive campaign against contact with animals during the outbreak”. of 2003 “.
According to the European Agency, “the possibility of further spread of this virus is very small.”
Dr. Amish Adalja, a senior researcher at the Johns Hopkins Center for Health Safety at the Bloomberg School of Public Health, said the virus would not be the first to enter a group of American animals.
Prior to 1999, the West Nile virus was unknown in the United States. Now, it is the leading cause of mosquito-borne diseases in the country.
This is unlikely to happen with the monkey line because “2003 had a good chance of this happening,” and it did not.
“What we are finding here, in real time, is that we know very little about what is happening and I think it is too early to offer comprehensive reassurance,” Worubi said.
It is not the mysterious beginnings and the silent spread of the monkey pox that make it difficult to predict its spread.
“It’s just a completely different epidemiological scene,” Remoen added.
She said, “What we know about the monkey line mostly comes from studies conducted in very remote rural communities in Central Africa, where transmission dynamics are certainly very different,” especially compared to “resource countries”. high in Europe or the United States “.
And a World Health Organization official noted Monday that although the epidemic is not yet considered a concern, it does not mean that certain groups are not at risk.
“Currently, we are not concerned about a global pandemic,” said Rosamund Lewis, technical director for the monkey line at the World Health Organization’s Health Emergency Program. They must be protected.
And she continued, “We are concerned that the world’s population has not been immune to orthopoxviruses since the smallpox eradication, so the virus may try to exploit some vulnerabilities and spread more easily among humans.”
A number of other unresolved questions can also change our understanding of the extent to which the virus spreads among humans. It is not clear, for example, how widespread it is when people have mild symptoms or the effect of mutations on the virus.
For these two points, Adalja responded that there is no reason for concern so far, explaining that the virus changes relatively slowly because its genome consists of double-stranded DNA, which is more stable than its RNA. coron viruses, for example.