A monkey making a meal of a squirrel might have sparked an outbreak.
In early 2023, mpox broke out amongst a gaggle of some dozen sooty mangabeys (Cercocebus atys) residing in Côte d’Ivoire’s Taï Nationwide Park. Roughly one-third of the monkeys developed signs resembling pores and skin lesions and 4 infants died. Surveys of the park’s wildlife revealed that the outbreak started after a member of the group ate a fire-footed rope squirrel (Funisciurus pyrropus), researchers report February 11 in Nature.
The findings counsel a rope squirrel was the supply of the outbreak and for the primary time present the monkeypox virus leaping from one species to a different within the wild. Viral spillovers from animals to folks are usually on the root of human mpox outbreaks.
Pinpointing which animals carry the virus might help information prevention measures that defend folks from getting contaminated, says Clement Meseko, a veterinarian and virologist on the Nationwide Veterinary Analysis Institute in Vom, Nigeria who was not concerned within the work. Officers may inform individuals who stay or work round fire-footed squirrels to put on private protecting gear when dealing with squirrels, as an illustration, or to scrub their palms.
A number of mpox outbreaks have popped up amongst Taï Nationwide Park’s primates since 2012, says Livia Patrono, a veterinarian and illness ecologist at Helmholtz Institute for One Well being in Greifswald, Germany. In 2012, an contaminated sooty mangabey turned up lifeless. Then members of three separate teams of chimpanzees (Pan troglodytes) fell sick in 2017 and 2018. However primates weren’t themselves harboring the virus. Researchers solely ever noticed mpox circulating in primates throughout outbreaks, not earlier than or after.
“One massive query for us has been, ‘the place are the nonhuman primates getting contaminated from?’” Patrono says. That’s why for years she and colleagues have been testing rodents within the park.
African rodents together with rope squirrels are among the many main suspects for mpox reservoir hosts — species during which the virus completely circulates. The primary monkeypox virus remoted from wildlife got here from a Thomas’s rope squirrel (F. anerythrus), and a number of squirrel habitats overlap with spots the place human epidemics have begun. Rope squirrel museum specimens from way back to 1899 have examined optimistic for the virus.
Intensive wildlife monitoring together with testing fecal samples discovered all through the park and conducting necropsies of lifeless animals allowed Patrono and colleagues to scrutinize how the 2023 mpox outbreak took off. The workforce examined greater than 700 trapped or lifeless rodents for monkeypox virus. Only one examined optimistic: a fire-footed rope squirrel discovered lifeless 3 kilometers south of the sooty mangabeys’ territory and solely 12 weeks earlier than the outbreak started.
Genetic analyses of the squirrel virus and the model that sickened sooty mangabeys confirmed that the viruses have been intently associated however not equivalent. The discovering means that whereas the lifeless squirrel didn’t spark an epidemic, one other may need.
Mangabeys do chow down on small mammals, and video proof from 2014 confirmed one of many park’s mangabeys consuming a fire-footed rope squirrel. To seek out out if squirrel was lately on the menu, the workforce examined mangabey fecal samples collected earlier than the outbreak for rope squirrel DNA. Two samples confirmed indicators of a fire-footed squirrel meal. A type of samples additionally examined optimistic for monkeypox virus and got here from the monkey believed to be the primary to get contaminated.
A feminine sooty mangabey eats a fire-footed rope squirrel in Taï Nationwide Park in December 2014. The archival video hinted that squirrel consumption might have sparked a 2023 mpox outbreak.
Taï Chimpanzee Venture, Alexander Mielke“That was a fairly, let’s say, informative piece of proof saying that [a fire-footed rope squirrel] was a really possible supply of an infection for the mangabeys,” Patrono says. Different rodents additionally possible carry the virus within the wild, that means extra species may additionally pose a menace.
