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The Contact

We’re 8000 feet above sea level, yet my shirt clings to my back from sweat borne of exertion and temperatures well over 90 degrees. Midday in equatorial Africa is hot, no matter the elevation.

Our group half-walks, half-slides down the mountainside, roots and vines our handholds as we try to follow a path carved by a forest elephant. It seems implausible that a creature of such size could navigate this terrain. Suddenly, our guide raises his hand.  He turns, places a finger against his lips, and points.  Craning my neck, I see a large, black hump blocking the trail about twenty yards ahead.  The jungle shadows obscure features. There’s a hint of movement, and suddenly a face materializes from the gloom, staring back at us.  Everyone gasps.  There, just ahead, is what we’ve been hiking all morning to see — a male silverback gorilla.

Any complaints we’ve had before now flee. We no longer care that we’ve been hiking for five hours through rising temperatures and elevations as we beat back thorny brush and biting bugs—all we can think about is the creature seated right in front of us.

The gorilla raises his eyebrows—such a human gesture—as he looks among our group. He turns his head but continues to watch us out of the corner of his eye as he snaps off a few nearby branches and begins to chew them. He has dismissed us while simultaneously tracking us. After a few moments he rolls to his feet and begins to move away down the trail. The word that comes to mind is lumber, as there’s really no better description for the movement of a 400-pound primate, but it doesn’t quite fit. Because in just a few steps the silverback is gone from sight, moving with a grace that belies his size.

We listen as he parts the underbrush and then all is silent. Other sounds begin to filter through: birds chirping and a breeze through the leaves overhead. It’s not that the jungle has reawakened around us; it’s more that we now realize there are other things around us besides the giant ape.

Our guide begins to move slowly down the mountain after him.  I feel the need to pinch myself. 

The Conflict

We’re hiking in such rugged terrain because this is where mountain gorillas make their home. Here, in a remote corner of southwestern Uganda, lies Bwindi Impenetrable Forest, one of only two areas in the world where mountain gorillas can still be found. Mountain gorillas (Gorilla beringei beringei) are critically endangered and divided in two isolated populations: one group within the Democratic Republic of Congo and Rwanda, and the second within Bwindi. Only about 1000 mountain gorillas remain in the wild, a number that—unique among primates—is actually rising.

Source: Wikipedia

The mountain gorilla remains a keystone species in all three nations from both a conservation and economic standpoint. Tourism plays a major role in their home nation economies as tourists pay a fee to visit with certain habituated gorilla families. For Uganda alone, estimates have placed the value of gorilla tourism between $7 - 33 million each year. Tourism also supports the local economies around the parks. The area encompassing Bwindi has one of the highest human population densities in the world, between three and four hundred people per square kilometer. The people living there practice mainly subsistence farming, with the majority living in “extreme poverty” based on their meager income. Tourist dollars therefore help bolster the local economies.

Mountain gorillas first gained international notoriety in the 1970s through the work of Dianne Fossey and National Geographic. Fossey focused on the mountain gorillas of Rwanda and became one of the first to call attention to the sustained poaching of these animals, working to prevent human-wildlife conflict in such a highly populated region. She was eventually killed, and her life and work would later be documented in the film Gorillas in the Mist.

Much of Fossey’s study—she opposed wildlife tourism due to the risk of disease transmission between humans and animals—augered current issues. An essential tenet of wilderness and environmental medicine is conservation of the natural environment. As we are currently well aware, we live in a time of unprecedented environmental change, change which has important implications to the stability of global ecosystems and human health. Large megafauna such as the mountain gorilla serve as indicators of the health of ecosystems and as an ecological proxy for environmental preservation.

Understanding threats to wildlife health, and the growing understanding of the interrelation between human and animal health, are important concepts driving wilderness and environmental medicine, and our group traveled to Uganda precisely for this reason. The group, funded in part by the 2017 Peter Hackett Young Investigator research grant from the Wilderness Medical Society, consisted of myself as medical faculty, family medicine residents, and veterinary students who had come to study markers of human-wildlife conflict.

Little did we know how much our work would presage the coming years.


The SARS-CoV-2 pandemic, much like the SARS and MERS-coronavirus mediated epidemics before it, has highlighted the transmissibility of infectious disease between humans and wildlife. In his 2012 book Spillover, author David Quamman documented the risk of such disease transmission previously, particularly evident in parts of the world where buffers between humans and animals do not exist.

Even before the current COVID-19 pandemic, wildlife-facilitated transmission of disease to humans—termed zoonotic disease—has been closely followed in the medical literature and lay media, and includes well known pandemics such as HIV/AIDS and outbreaks of Ebola hemorrhagic virus. Less publicized is the anthropozoonotic (human to wildlife) transmission of disease, including reports of metapneumovirus transmitted to chimpanzees and gorillas and transmission of chronic pathogens to wild apes, including antibiotic-resistant enteric bacteria in Uganda.


The close genetic similarities between humans and gorillas increases the risk of disease transmission between these two species, threatening the mountain gorillas, the tourism economy based on them, and the health of the humans living on the forests’ borders. As the human populations around the parks continue to grow, increased human-wildlife interaction and conflict is unavoidable. To mitigate these risks, wildlife veterinary teams have been established in Uganda to monitor the gorillas’ health, both those habituated to human tourism and those not. It was while hiking through the forest one day that a young wildlife veterinarian named Dr. Gladys Kalema-Zikusoka, the first female to hold such a position in the country, would find the body of an infant gorilla that had died due to complications from an intense infestation of mange. Caused by the Sarcoptes scabiei mite—the same pest that causes scabies in humans—such a find proved highly alarming, as the infant was from one of the wild, non-habituated gorilla families. The search for how a disease of humans had made its way so deep into a national park started the young veterinarian on a path that would change her career. Dr. Gladys’s uncovered an answer she could not have imagined, one that led to an entirely new way of thinking about conservation in eastern Africa—and which will be detailed in the following installment.

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