Squirrels, Armadillos and Now Apes Have Leprosy

Two colonies of apes have been discovered suffering from leprosy. The so-called “Leper Apes,” some with gruesome skin lesions and rotting body parts, were found in Guinea-Bissau's Cantanhez National Park and in Taï National Park and the Ivory Coast, in West Africa.

Hansen's disease (also known as leprosy) is an infection caused by the slow-growing Mycobacterium leprae bacteria. The disease affects the nerves, skin, eyes, and lining of the nose (nasal mucosa). According to Britannia the disease originated on the Indian subcontinent 4,000-years ago and by 1200 AD an estimated “19,000 leprosy hospitals existed all over Europe.”

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Today, with early diagnosis and treatment, the disease can be cured. However, Professor Fabian Leendertz from the Robert Koch Institute and working with these leper ape colonies told the Daily Mail that although treating leprosy in humans is relatively easy, deploying antibiotics to wild chimpanzees “would be a real challenge.”

Disease progression of leprosy in chimpanzees at Cantanhez National Park, Guinea-Bissau. (Hockings et. al. / nature)

Leprosy Among Animals is a Very New Phenomena

Even though the shocking images showing apes with the tell-tale leprosy lumps on their faces are soul destroying, please read this article guilt-free. You should know here at the beginning of the story that these leprosy strains are not “jumping” from human populations. This is according to a new paper in the journal Nature that was published by a team of scientists from the Centre for Ecology and Conservation, University of Exeter, in England.

While the origins of the infections are at this time still unclear, the disease is suspected to be circulating in “more wild animals than was previously suspected,” explains an article in the Daily Mail. The reason we shouldn’t be jumping too quickly to the conclusion that humans are the main vector of transmission is because the disease has been controlled in humans with antibiotics in the UK since the 1980s, yet red squirrel populations in the UK and armadillos in the Americas are also spreading the disease.

A chimpanzee named Woodstock with leprosy in Ivory Coast. (Tai Chimpanzee Project)

An Ancient and Effective Primate Eater

Lead author Dr. Kimberley Hockings, wrote in the paper that this is the first confirmation of leprosy in non-humans in Africa. Professor Anne Stone, an evolutionary geneticist at Arizona State University who was not involved in the study, told the Daily Mail that leprosy dates back millions of years “and may have inflicted primates long before humans evolved.” And even with advanced medicines, the World Health Organization still record “around 200,000 cases of leprosy every year,” mostly in its country of origin - India.

The team of scientists first noticed symptoms of leprosy in the population of chimpanzees in Guinea-Bissau. It was later discovered the symptoms appeared to be “strikingly similar to those suffered by humans with advanced leprosy, including lesions and "claw" hand,” explained Hockings. The leprosy outbreak was also confirmed during a post-mortem examination of an older female and in fecal samples of an adult male.

Illustration of elderly male patient with leprosy in 1889. (Wellcome / CC BY 4.0)

It Won’t Be A Disease, It Will Be Us…

Professor Leendertz said leprosy in humans is easily treated with antibiotics, with sufferers returning to clinics every week over several months. However, the impact of the disease on chimpanzees is harder to manage, for they are allegedly terrible at keeping appointments. Well, for obvious reasons.

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At the moment the infected chimpanzees seem to be “coping with their illness, although one is losing weight” claims the new study. There is more good news in that leprosy is not currently threatening to spread throughout the two groups. And as I said earlier, the researchers suspect “something else other than humans is actually the main host,” so don’t you be thinking we are now killing monkeys with human diseases. No. We do that by tearing apart their natural habitats mining for minerals.

Top image: A chimpanzee named Woodstock with leprosy in Ivory Coast. Source: Tai Chimpanzee Project

By Ashley Cowie