For years, African scientists have been following a sharp rise in cases of monkeypox.
In 2018, more than 2,800 suspected cases were reported in the Democratic Republic of the Congo alone. The following year, there were about 3,800.
In 2020, half a century after the first human infection was found in the central African country, then known as Zaire, the total number of suspected annual cases was approaching 6,300, including 229 deaths.
The clear rise in infections occurred as globalization increased, humans continued to invade animal habitats, and the cross-protection offered by decades of smallpox immunization campaigns began to wane. Given that perfect storm, many scientists were not surprised by the recent appearance of monkeypox in other parts of the world.
Some also warn that this will not be the last time the virus has spread beyond its typical territory.
“The recent outbreaks are a kind of culmination of years of warnings that were basically ignored,” said Dr. Boghuma Titanji, an infectious disease scientist and doctor at Emory University in Atlanta who is originally from Cameroon.
“Because, unfortunately, smallpox is a disease that has traditionally caused outbreaks in Africa, and usually in very remote parts of Africa, and affects populations that the world doesn’t always care about.”
The monkeypox virus, known to cause revealing skin lesions, usually enters human populations when someone touches or eats infected wildlife. (Melina Mara / The Washington Post / Getty Images)
“Our fears are being confirmed”
The monkeypox virus, known to cause revealing skin lesions, usually enters human populations when someone touches or eats infected wildlife. From there, it can spread through close contact, including airborne droplets, skin-to-skin contact, or contact with contaminated surfaces such as clothing or bedding.
Most researchers studying emerging viruses have long been concerned that it could “evolve to fill the ecological niche” left behind when a similar virus, smallpox, was eradicated through global immunization programs, Titanji told CBC News .
“If given the chance to spread uncontrollably … it could improve on infecting humans and cause larger outbreaks than we’ve seen in the past,” he added.
The incidence of human smallpox “increased dramatically” in rural Congo during the decades following the cessation of mass smallpox vaccination, researchers warned in an article published in 2010 in the peer-reviewed journal Proceedings of the National Academy of Sciences.
In Nigeria, more than 500 cases of monkeypox have been reported since 2017, including a handful of deaths, and the actual number could be higher, given the limited surveillance of the spread of the virus in rural areas, he said. Dr. Oyewale Tomori, a Nigerian virologist.
“The longer we are away from the smallpox vaccine, the more likely it is to start spreading smallpox,” said Tomori, a board member of the Global Virome Project and former chairman of the Nigerian Academy of Sciences.
“We’ve been saying this for a long time. Now our fears are being confirmed.”
TARGET | How monkeypox outbreaks usually develop in endemic regions of Africa:
The virologist explains how smallpox outbreaks of monkeys usually develop in endemic regions of Africa
The virologist Dr. Oyewale Tomori describes how smallpox outbreaks are common in regions where the virus is endemic.
Climate change-driven animal migration and deforestation are also fueling more human-animal interactions, Titanji said, making it easier for viruses like monkeypox to spread wildlife to human populations.
“Because the world is as interconnected as it is, a traveler from an endemic country, such as Nigeria, Cameroon or Cameroon, takes less than 24 hours. [Congo]to get to Europe or North America or South America, or anywhere else on the planet, “he said.
Spreading out of Africa is not a big surprise, said Dr. Beatrice Nguete, a doctor and researcher on smallpox in the Kinshasa School of Public Health in the Congolese capital.
“All communicable diseases have the potential to move,” he said. “You have a person visiting an endemic [area]or an area where an outbreak occurred, you have that possibility. “
Recent increase in world travel
But why now, exactly?
Cases of monkeypox have already arisen sporadically in other countries before, usually with ties to travel, but not on the scale of the current outbreak in several countries where local transmission is clear.
Hundreds of cases have been reported on several continents so far, mostly among men, with more than 50 confirmed or suspected infections being investigated in Canada.
They include a child in Quebecwho went to school after being exposed.
There is still no concrete evidence that the virus has mutated, according to World Health Organization (WHO) officials, although global teams are still analyzing samples.
Instead, Dr. David Heymann, WHO’s senior adviser and former head of its emergency department, recently suggested that the unprecedented global outbreak was a “random event” and probably linked to radish transmission held in Europe.
A teenager is examined by a doctor on suspicion of smallpox in the Republic of Congo in August 2017. (Melina Mara / The Washington Post / Getty Images)
Sometimes people can be contagious with monkeypox for almost a month, even a day or so before the lesions appear on the skin, giving the virus a long time to transmit. This means that a high number of cases in Africa and more mobility after a long journey during the COVID-19 pandemic could be providing the ideal conditions for its rapid spread.
“We are seeing a huge increase in global travel, as we have never seen in the last three years,” said Dr. Abdu Sharkawy, an infectious disease specialist at the University Health Network and an assistant professor of medicine at the University. of Toronto.
Given the unusual nature of current transmission patterns, there is also the possibility that the virus was spreading worldwide, undetected, for quite some time, until doctors outside Africa realized what they were seeing. , said Dr. Michael Libman, director of the JD MacLean Center for Tropical. Medicine at McGill University in Montreal.
“If it has evolved in a certain way, that could make it slightly different from what we’ve dealt with in Africa in the past,” he said.
WHO warns of “more transmission”
Persistent questions about the current global outbreak make it difficult to predict how it will develop. But monkeypox outbreaks in Africa tend to flow and go down, said Tomori of the Global Virome Project.
“We don’t see fast transmission as seen with COVID, for example,” he said. “But it also goes out almost in a few months after a generation or two of spread … and it suddenly reappears.”
Officials in Canada, the United Kingdom and many other countries they also chase ring vaccination Strategies for Cutting Virus Transmission Chains Using inoculate certain high-risk individuals —Such as close contact with people suspected of being infected — with smallpox injections.
However, Dr. Hans Henri P. Kluge, WHO Regional Director for Europe, issued a statement on Tuesday highlighting its concern that the “potential for greater transmission in Europe and elsewhere during the summer is high”, given the number of major festivals and festivals expected in the coming months.
TARGET | How does ring vaccination work ?:
How “ring vaccination” could help contain the spread of monkeypox in Canada
“Ring vaccination,” rather than the mass vaccination used for COVID-19, is the likely way to contain the spread of monkeypox in Canada, says Dr. Samir Gupta.
“From now on, an effective response to monkeypox will not require the same extensive population measures we needed for COVID-19 so that the virus does not spread in the same way,” he continued. “But, and this is important, we still don’t know if we will be able to contain its spread completely.”
Officials at the European Center for Disease Prevention and Control also warn that if the monkey’s smallpox is infested with local wildlife, it could become endemic to this continentas in some parts of Africa, in reference to when a virus is constantly circulating within a specific region.
“If current trends continue, and there’s no reason to believe they shouldn’t, we’ll see many more cases, and we’ll see them in a very diverse range of geographic areas,” T’s Sharkawy’s U said. to say.
Given the possibility of continued spread and future outbreaks, Emory University’s Titanji said it is crucial that the global public health community pay more attention to the transmission of the virus from animal to human, both for smallpox of the monkey as for other emerging pathogens.
“When these outbreaks in North America and Europe finally end, will we once again ignore the overflowing events that have been going on for the last 50 years in Africa?” she asked.
“Or will we invest more significantly to better monitor the virus and better protect these populations to actually stop contagion events at their source?”