The different MPOX epidemics in Africa respond to different logics, shows a study published on October 24, 2024, noting that the new variant of the virus is transmitted mainly between humans while contaminations by animals remain the majority for the older version. Human cases of MPOX in the Democratic Republic of Congo (DRC) are driven by two transmission patterns", summarizes this study, published in the journal Cellular.
Several outbreaks of MPOX, also known as "monkey pox", are currently underway in the DRC and, to a lesser extent, in neighbouring countries. They are fuelled by two different versions of the virus, clade 1 which has been circulating for decades, and clade 1b, a new variant. The latter was notably identified in a patient in Germany, one of the very few cases where this version has been detected outside the African continent.
A global epidemic of MPOX, a disease that causes multiple skin lesions, has also been ongoing since 2022 but involves a different version of the virus, called clade 2.
Understanding the specificities of each version
This complex situation, which led the World Health Organization (WHO) to declare MPOX as a Urgent worldwide, pushes researchers to question the specificities of these different versions, whether in terms of dangerousness, contagiousness or modes of transmission. It is on this last point that the study of Cellular leaned over.
Historically, MPOX is in fact mainly known for being transmitted through contact with animals, particularly through the consumption of contaminated flesh. But recent epidemics also seem to be linked to contamination from one human to another, particularly during sexual intercourse.
Credit: Sabrina BLANCHARD / AFP
The study, which is based on the genetic analysis of viruses taken from several hundred patients, concludes that both logics are at work. Cases linked to version 1a seem to mostly come from contamination by different animals, while variant 1b much more often presents a mutation typical of its adaptation to humans. This therefore suggests that it is first transmitted from one human to another.
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