The saying that forewarned is forearmed is ringing a bell in the ears of African wildlife conservationists. 

This follows detection of leprosy among two groups of unconnected populations of chimpanzees in Guinea-Bissau and Ivory Coast in West Africa.  

Sam Mwandha, the executive director of Uganda Wildlife Authority (UWA), said leprosy was wiped out of Uganda many decades ago. 

He said there is no known history of leprosy among primates, including chimpanzees in Uganda.  

“We have good health systems that eradicated leprosy,” he said, adding that Uganda’s primate population is not at any risk of catching the disease.

Commenting on Uganda’s preparedness to contain an emergency of zoonotic diseases, including the outbreak of coronavirus, Mwandha said social distancing is the game-changer.  

He also said Uganda’s visitors to the primate parks are limited in number because the country promotes eco-tourism as opposed to mass tourism.  

“The visitors are limited to avoid transmission of diseases to the animals and also infection of the human population by the animals,” Mwandha said.  

He said there is a worrisome trend in western Uganda, particularly Hoima, where chimps escape from the protected areas into people’s farmland and settlements. 

Mwandha attributed this to the rampant destruction of the environment, including forests that have always sheltered the chimps. 

“We have many cases where chimps get out of the protected areas looking for food,” he said, adding that their habitats have been converted into farmland and settlements. 

 Leprosy in West Africa 

According to an analysis published in the journal Nature last week, a new study found Leprosy in wild chimpanzees in Ivory Coast and Guinea-Bissau for the first time. 

The study shows the strains of leprosy are different, and both are uncommon among humans. 

The origins of the infections are unclear, but the research team led by the University of Exeter and the Robert Koch Institute says the findings show leprosy is probably circulating in more wild animals than was previously suspected, either as a result of exposure to humans or other unknown environmental sources. 

 Humans are considered the main host for Mycobacterium leprae bacteria, which cause leprosy, but “spill-over” to other mammals such as nine-banded armadillos and red squirrels is known to occur. 

“This is the first confirmation of leprosy in nonhuman animals in Africa,” said the lead author Dr Kimberley Hockings, of Center for Ecology and Conservation in Cornwall, according to a press release from the University of Exeter.

“We first noticed possible symptoms of leprosy in a population of chimpanzees in Guinea-Bissau. 

“The symptoms appeared to be strikingly similar to those suffered by humans with advanced leprosy, including lesions and 'claw' hand.” 

Following these findings, Prof. Fabian Leendertz from the Robert Koch Institute and Dr Roman Wittig from the Max-Planck-Institute for Evolutionary Anthropology identified further cases of leprosy at their study site, Tai National Park, Ivory Coast. 

 Dr Hockings added: “In Guinea-Bissau it is possible that chimpanzees somehow acquired leprosy from humans in this shared landscape, although people do not kill or eat chimpanzees. 

Professor Leendertz added: “In the Ivory Coast, chimpanzees are more distant from human settlements, and it seems more likely that the chimpanzees acquired the infection from another animal species, or from an environmental source such as ticks or bacteria living in the water.” 

Leprosy in humans is easily treated with medication, but the impact on chimpanzees is hard to predict. 

“Long-term health monitoring and research are needed to establish the scale and possible effects of leprosy among wild western chimpanzees,” said Dr Wittig. 

The international research team included authors from West Africa, Europe and the USA. 

This story is part of the CABI, SciDev.Net and Robert Bosch Stiftung Script science journalism project.