Monkeypox: 5 minutes to understand WHO concerns about global spread

Could cases of monkeypox spread around the world? The World Health Organization (WHO) is concerned about this following an outbreak in the Democratic Republic of Congo (DRC) in recent weeks. What new observations have been made? What is the patient profile? Le Parisien sums it up.

What is the situation?

The anxiety is real. “We fear that there is international transmission” from the DRC, Dr. Rosamund Lewis, a smallpox specialist at the WHO (the preferred term replacing “monkeypox”), said Friday during a press briefing in Geneva. Because the observation is alarming: “the epidemic is spreading rapidly throughout the country.” More than 13,000 suspected cases have been reported, “more than double the number of infections reported in previous years,” she warned. First of all, “more than 600” people died.

Before this, about ten regions of the DRC were considered “endemic,” meaning that the virus was circulating there on a more or less constant basis. According to a WHO bulletin dated November 23, 22 provinces in the country are currently affected by smallpox. People “who traveled to endemic regions were at the origin of the chain of human-to-human transmission in unaffected provinces,” the UN agency points out.

Why are these pollutants more of a concern than before?

There are two known clades (or variants) of mpox: 1 and 2b. The current epidemic in the DRC is carried by clade 1 of the virus, while the one that hit Europe and the United States last year was caused by clade 2b, which could be transmitted mainly during sexual intercourse. “Until now, clade 1, present on the African continent, was transmitted to humans through contact with certain animals, such as rodents. These cases continued to be limited to rural areas. However, this is the first time that sexual transmission has been observed among patients suffering from variant 1,” explains Dr. Eric D’Ortensio, an epidemiologist at ANRS Emerging Infectious Sciences.

This new mode of transmission is worrying as the epidemic is now spreading to regions hitherto considered free of the tropical disease. “Semi-urban or very urban areas such as Kinshasa” or Lualaba and South Kivu provinces are now affected, he notes. The patient profile has also changed, with more women than men becoming infected.

Another concern is that variant 1 circulating in the DRC represents a more alarming level of severity than variant 2b. “Historically, we estimate the mortality rate for group 1 to be around 10%, compared to 1% for group 2,” notes Yannick Simonin, an expert on emerging viruses at the University of Montpellier, even if these figures depend on the health of the individual. country and the quality of its support.

What’s the context?

Monkeypox virus has been endemic in parts of Africa since the 1970s. The disease is transmitted from animals to humans, but is therefore also capable of transmission through close contact and sexual contact. Last year, an outbreak of cases (associated with variant 2b) was observed as early as May 2022 in Europe and the United States.

Symptoms begin with fever, fatigue, or even muscle pain. Then spots and rashes may appear on the skin (including the genitals). The PCR test then allows you to confirm or not the presence of the virus. Faced with a surge in cases in 2022, some countries such as France and the United States have stepped up their vaccination campaign. In France, the epidemic is also considered “under control.” The fact remains that infection rates are now rising in several regions of the world, especially in Asia, with cases occurring in Japan, Vietnam, China and Indonesia.

What kind of prevention?

To curb any outbreak, efforts must first focus on detection campaigns, which are still considered too fragile. “The diagnosis is difficult because the symptoms of MPOX can easily be confused with those of other diseases, from a simple flu-like illness to measles with a skin rash,” says Yannick Simonin, who believes that “a significant proportion of positive cases” are still flying under the radar. To summarize: “Lack of detection is a fertile breeding ground for the spread of the virus.”

Supporting research projects and increasing attention to ongoing research will better identify the populations that may be most affected, adds Dr. Eric D’Ortensio, who is involved in one of them, the Panafpox project with ANRS. The task is no small one. “Last year we saw very localized circulation of the virus among men. But in the DRC we are seeing a wider spread among the population, which encourages caution and avoidance of any stigmatization of the homosexual community, points out Yannick Simonin.

Finally, strengthening vaccination campaigns, which are “almost non-existent” in Africa, could combat the spread of smallpox. About a million doses have been administered worldwide, including about two-thirds of the first injections, the researcher said. Coverage is still considered “insufficient” to prevent a potential resurgence of the epidemic in France, as in other countries, he said.