Rope squirrels have long been suspected of being a reservoir of mpox. But evidence of the virus jumping from a squirrel to another animal had never been documented.
In January 2023, researchers at the Helmholtz Institute for One Health in Germany noticed that a baby monkey known as a sooty mangabey had developed reddish skin lesions on its forehead, chest and legs. Within 48 hours, the animal was presumed dead.
In the following weeks, nearly a third of the group’s 80 members developed similar injuries, and four cubs died. The outbreak was caused by virus mpox (MPXV).
Now, a study recently in Nature traced its origins to a small African rodent called fire-footed rope squirrel (Funisciurus pyrropus).
The researchers had a “unique opportunity to describe the transmission of the virus from a reservoir to a host in real time,” the study’s corresponding author, disease ecologist, told Reuters. Fabian Leendertz.
Os Rope squirrels have long been suspected of being a reservoir of mpox. However, evidence of the virus jumping from a squirrel to another animal has never been documented.
About 12 weeks before the mangabey outbreak began, a dead firefoot squirrel was found in Taï National Park in Côte d’Ivoire.
“We were surprised because squirrels are normally small animals in the rainforest, they decompose very quickly, they disappear quickly,” Leendertz pointed out.
A necropsy on the squirrel carcass, which tested positive to MPXV.
The researchers were even able to isolate viable MPXV from his skin, lung and liver. When the team sequenced the virus from the squirrel and the dead mangabeis – details Refractor -, they discovered that the virus genomes were identical.
The wrong squirrel, at the wrong time…
However, it was not the dead squirrel that started the outbreak, as it was found 3 km from where the monkeys lived. “It was another squirrel”said the veterinarian.
O virus probably circulated through the forest among the squirrel population, and “the monkey was unlucky when he ate the wrong squirrel”, numa deadly chain.
“Firefoot squirrels are one of the potential reservoirs, but there will be more species of rodents”, warned Leendertz.
The researchers also suggest the possible transmission of the virus to humans. Fire-footed ground squirrels are hunted and consumed by humans in West and Central Africa, with transmission also occurring through infected mangabeys and humans.
“If a hunter enters the forest and kills one of the monkeys with injuries, he will also will take the virus home”, concludes Leendertz.
