Leprosy is a particularly disturbing and painful disease that was mostly found in humans — that is, up until recently. Now, researchers have spotted the disease in chimpanzees giving cause for alarm.
The news was reported by Science Magazine who quoted wildlife veterinarian Fabian Leendertz stating: “I have NEVER seen this in chimps." The illness was spotted in several of the animals at Cantanhez National Park in Guinea-Bissau, and in another more than a thousand miles away at Taï National Park in Ivory Coast.
According to the publication, the disease is caused by the bacteria Mycobacterium leprae and it has been spotted before in other animals, such as the nine-banded armadillos in the Americas and red squirrels in the United Kingdom. In these cases, there is reason to speculate the illness jumped from humans to animals as both species carry the same bacterial genotype that was identified in human outbreaks back in Medieval Europe.
Not transmitted by humans
However, when it comes to the newly infected chimps, two rare genotypes — 2F and 4N/O — have been identified. This means that the leprosy source is likely in their natural environment, ruling out human transmission.
“The most likely scenario is that there is some unidentified leprosy reservoir,” Leendertz explained. The report also quoted John Spencer, an immunologist who studies leprosy at CSU, who said that the disease "... is not limited solely to exist in humans, but has other niches that it has adapted to.”
In addition, Anne Stone, an evolutionary geneticist at Arizona State University, Tempe, who was not part of the study, told Science Magazine that the disease's genome’s small size and other quirks are all indicative that it may be thriving in another reservoir.
“That’s really a signature of something that needs to live on another organism,” concluded Stone. Still, the researchers, for now, remain baffled as to where the disease's source may be.