Cases of leprosy have been confirmed among two unconnected populations of West African chimpanzees, in Guinea-Bissau and Côte d’Ivoire, according to images released by a team of researchers.
Although the origins of the infections are unclear, scientists at the Center for Ecology and Conservation at the University of Exeter (England) say the disease is likely circulating in more wildlife than previously suspected.
This could be due to “exposure to humans or other unknown environmental sources,” they added.
Humans are considered to be the primary host for the bacteria Mycobacterium leprae, which causes leprosy, but there is an “overflow” to other mammals. It has been controlled in humans with antibiotics since the 1980s.
A real challenge
Researchers once believed that leprosy had been wiped out in the animal kingdom. But over the past two decades, scientists have found that it spreads among red squirrels in the UK and armadillos in the Americas. And now for the wild chimpanzees.
Leprosy is an infectious disease of the skin and nerves which, if left untreated, can lead to deformities and blindness.
In humans, the prevalence of leprosy depends on access to treatment, but no chimpanzee in the wild has ever received treatment.
Indeed, leprosy is easily treated in humans, but administering antibiotics to unaccustomed wild chimpanzees would be a real challenge.
Although the study is the first to report the disease in wild chimpanzees, there have been cases in captive chimpanzees, the researchers said.