Dubai, United Arab Emirates (CNN) – Monkeypox continues to spread in countries where this virus is not normally endemic, which puts global health officials on high alert.
Currently, with more than 643 monkeypox cases 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 appearance of monkeypox in many countries at the same time indicates that perhaps There has been undetected transmission of the infection for a while.”
This virus has been spreading in countries located in West and Central Africa for decades. In preliminary research published this week, scientists at the University of Edinburgh’s Institute of Evolutionary Biology describe how the genotype they see suggests that “there has been continuous human-to-human transmission since at least 2017”.
The genetic sequences in this research showed that the first monkeypox cases in 2022 resulted from a spread of the virus that led to the emergence of infections in Singapore, Israel, Nigeria and the United Kingdom, between 2017 and 2019.
“This spread of the virus has been going on 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 who live in areas with limited resources, where the disease is endemic, and to control it in its homeland, before it spread globally.
“It’s really the story of a two-wave outbreak,” Worubi explained, “noting that we actually need to turn our attention to where it was spreading…and pay attention to these populations, as much as we care about what’s happening in every other country in the world.”
If research continues to show that the virus has spread more from humans than previously thought, rather than from animals to humans, according to Worubi, one of the “really good questions” is, why didn’t the world think monkeypox might be endemic in places outside West and Central Africa?
Determining the date of its publication: unknown
Epidemiologist Anne Remoen has been studying monkeypox for nearly 20 years and has repeatedly warned that its spread in places like the Democratic Republic of the Congo could have wider global health implications.
“If monkeypox become endemic in a wildlife community outside Africa, it will be difficult to reverse a public health reversal,” Rimoin, an epidemiology professor at UCLA Fielding School of Public Health, warned in a 2010 article in the Proceedings of the National Academy of Sciences.
The recent outbreak of monkeypox is proving difficult to predict, in part because we have not been able to fully trace its origins.
“We don’t even know when it started spreading,” Rimoen added. “It is likely that it has been spreading silently for some time.”
Previous human cases of monkeypox have not been seen beyond initial exposure to an infected animal, usually a rodent. Once this virus spreads among these animals, it can continue to transmit to humans.
Remoen told CNN that if we witness a sustainable transmission of this virus from one person to another, albeit at a low rate, this would suggest transmission of infection again to animals in non-affected countries from a source of “an existential threat to a clear possibility.” This fact allows the virus to survive in an environment, and to pass between animals and humans over time.
“We know a lot about this virus, but we don’t know everything about it,” Rimoen noted, so “we will have to study this reality very carefully.”
Too early to give reassurances
WHO officials have stated that the global public health risk of this virus is moderate.
According to the risk assessment report issued by the World Health Organization, on Sunday, “public health risks could become high if the virus takes advantage of the opportunity to establish itself as a human pathogen, and spreads among groups most vulnerable to severe disease, such as young children, and people with weakened immunity.” “.
The organization asked “countries to take immediate measures to reduce the spread of the virus among vulnerable groups, and among the general population, and to avoid viewing monkeypox as a clinical condition and a public health problem in currently non-endemic countries.”
During a press conference last week, a US Centers for Disease Control and 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 it wouldn’t.
“I think we’re still in the early days of our investigations,” said Dr. Jennifer McQuiston, deputy director of the CDC’s Division of Pathogenesis and Pathology.
McQuiston noted that the virus was not endemic after the last monkeypox outbreak in the United States, in 2003, when prairie 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 own assessment with McCuston last week, noting that there was no evidence that the virus had established itself in US wildlife after authorities launched an “aggressive campaign against animal contacts during the 2003 outbreak”.
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 Security at the Bloomberg School of Public Health, said this virus would not be the first to enter a group of American animals.
Prior to 1999, West Nile virus was unknown in the United States. Now, it is the leading cause of mosquito-borne diseases in the country.
It is unlikely that this would happen with monkeypox because “2003 had a good chance of that happening”, and it did not.
“What we’re finding here, in real time, is that we know very little about what’s going on, and I think it’s too early to offer comprehensive reassurances,” Worubi said.
Different purpose
It is not the mysterious beginnings and the silent spread of monkeypox that makes its spread difficult to predict.
“It’s just a completely different epidemiological scene,” Remoen added.
She said, “What we know about monkeypox most prominently comes from studies conducted in very remote rural communities in Central Africa, where the transmission dynamics are certainly very different,” especially compared to “high-resource places in Europe or the United States.”
And a World Health Organization official noted Monday that although the epidemic is not yet considered a concern, this does not mean that certain groups are not at risk.
“Currently, we are not worried about a global pandemic,” said Rosamund Lewis, technical lead for monkeypox in the World Health Organization’s Health Emergencies Programme. they need to protect themselves.
And she continued, “We are concerned that the world’s population is not immune to orthopoxviruses since the eradication of smallpox, so the virus may try to exploit certain vulnerabilities and spread more easily between people.”
A number of other unresolved questions could also change our understanding of the extent to which the virus spreads between people. It’s not clear, for example, how much spread when people have mild symptoms, or the effect of mutations on the virus.
On these two points, Adalja replied that there is no cause for concern so far, explaining that the virus mutates relatively slowly because its genome consists of double-helix DNA, which is more stable than the RNA of corona viruses, for example.