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Mountain gorilla trekking is Uganda’s biggest foreign currency earner. Approximately 8,000 tourists visit these majestic animals in Bwindi Impenetrable Forest National Park’s annually. This earns the landlocked African nation an estimated $4 million USD annually. In mid-2021, there was an estimated at 350 individuals, of which 225 individuals (divided into 10 groups) are used to human presence (the other 125 mountain gorillas remain unhabituated). There are fewer than 900 mountain gorillas in existence.

The Great Apes are our closest genetic kin. Therefore, this makes us humans, gorillas (Gorilla gorilla), bonobos (Pan paniscus), chimpanzees (Pan troglodyte) and orangutans (Pongo borneo) even more susceptible to each other’s’ ailments such as scabies, measles, dysentery, tuberculosis, diarrhea, influenza, among others (over the past two decades thousands of lowland gorillas and chimps in the Congo Basin region of central Africa have been killed by the deadly Ebola Virus and during the recent Covid-19 pandemic and Ebola outbreaks national parks that offered mountain gorilla tourism in central Africa shut their gates).

Habitat encroachment leading to habitat loss is a ubiquitous threat to Virunga National Park’s spectacular biodiversity. For example, illicit charcoal production and slash and burn farming activities employed for energy and income generation, are key causes of habitat loss. New settlements from people fleeing conflict within the region also encroach on Gorilla territory.

Such illegal proximity to humans can have fatal outcomes. In August 1996, Gladys Kalema-Zikusoka, a young veterinary officer having trained at the University of London’s Royal Veterinary College was at the time working for the Uganda Wildlife Authority (UWA) , was faced with a deadly outbreak of scabies (Sarcoptes scabiei) that affected the country’s critically-endangered mountain gorillas in Bwindi Impenetrable National Park in southwest Uganda.

Scabies is a debilitating skin infection that also affects humans (the scabies which affected the Bwindi gorillas was genetically identical to that which infected the human population around the forest. The mites were transmitted through human contact).

All four members of a gorilla group which had been habituated to tourists were clinically affected; one infant male was most severely affected and later died. Gladys’s suspicion was that the infant had been infected with human skin mites, which made the ape to lose its hair and develop scaly skin. A juvenile male showed serious symptoms of the disease and the two adults had milder symptoms. But the three older animals recovered after jabs of ivermectin, a broad-spectrum anti-parasitic medication (during the height of the Covid-19 pandemic the drug was being touted as a treatment and preventative for the deadly disease) . Scabies and pneumonia were the cause of the deaths, diseases that humans suffer from.

But that was not the end of it. Four years later, another scabies outbreak not only infected 15 more gorillas at the southern end of Bwindi Park, but led to a two year postponement of tourist visits to this group.

The scabies that the gorillas contracted are endemic in local communities and is due to poor hygiene. But the mountain gorillas themselves are no innocent bystanders. Our close cousins have a voracious appetite for not only some of the local subsistence food crops such as matooke, a ubiquitous green cooking banana, but also for eucalyptus trees that were planted by communities bordering the park to to mitigate the effects of deforestation. Such raids results in conflicts between people and gorillas. They also put gorillas at greater risk of contracting preventable infectious diseases from


During the mid-1990s, ‘Conservation Medicine’ was still an emerging discipline. Also known as ecological/environmental medicine, conservation medicine is the study of comparative human and animal health and natural environmental conditions. Later, community health education workshops revealed that communities benefiting from tourism saw the advantages of improving their health and hygiene to protect a sustainable source of income from gorilla ecotourism.

Photo: The renowned mountain gorilla Poppy with her baby. Poppy was Diane Fossey’s favorite gorilla but sadly passed away in 2019.

Gladys was strongly influenced by the conservation medicine movement as well as by the fact that rural Ugandans living in close proximity to mountain gorillas areas believed that good health and hygiene in their community could have healthy economic benefits for them as well.

It was a path that led to the establishment of Conservation Through Public Health (CTPH), a private non-profit organization that promotes conservation and public health by improving people and animal primary healthcare in and around protected areas in Africa. CTPH also helps to prevent the spread of diseases from wild animals to humans and vice-versa.

The main innovative aspect of CTPH is that it takes into consideration the interconnection between Uganda's wildlife management and rural public health programs, and aims to manage them jointly.

“It is the case throughout sub-Saharan Africa, and all around the world that public health programmes are managed separately from conservation programs in wildlife-protected

areas,” Gladys explained to me over a decade ago. “This is because traditionally, the programs were managed separately, with little to no communication or collaboration between the key sectors.”

In many wildlife-protected areas in Uganda, communities and wildlife share habitats, living closer than ever before. One factor that has created this situation is population increase. Uganda has one of the world’s highest fertility rates. In 1959, the country’s population was 6.5 million but just over two generations later it has swelled to 47 million. In addition to population rise is the issue of land scarcity. Most Ugandans are small-scale subsistence farmers but arable land is increasingly scarce.

According to their website, CTPH today has 30 employees and 270 volunteers from the communities CTPH trains. Each village helper looks after around 40 households and advises them on topics such as hygiene, family planning, sustainable agriculture and nature conservation.

Photo: The late HRH Prince Philip with Lawrence Zikusoka, Gladys’ husband, tours CTPH’s telecenter at Queen Elizabeth National Park, western Uganda.

Since the time of the scabies outbreak, Gladys has gone from strength to strength. Between 1996 and 2000, she established the first Veterinary Unit at the UWA, and not only has she become a National Geographic Emerging Explorer, but has been the recipient of several prestigious international awards including, most recently, the 2022 Tallberg-SNF-El iasson Global Leadership Prize, the 2011 Women of Discovery (WINGS WorldQuest) and the 2009 Whitley prize.

Conservation efforts with the mountain gorillas of Bwindi Impenetrable Forest have also proved very effective. In fact, today there are an estimated 460 animals in Bwindi alone. Their population increase in the Virunga mountains (extinct volcanoes spanning Rwanda, eastern Democratic Republic of Congo and Uganda) has been one of the world’s rare conservation success stories.

Sadly, most of Africa’s other primates aren’t so lucky.

According to the 2017 report, ‘Impending Extinction Crisis of the World’s Primates: Why Primates Matter’ the populations of 75% of primate species are decreasing globally. A year earlier, at the IUCN/SSC Primate Specialist Group African Primate Red List Assessment Workshop held that April in Rome, Italy, experts assessed the conservation status of Africa’s primates and, to their astonishment, discovered that 100 out of 179 population groups known as taxa were classified as Threatened, with 35 Endangered and 15 Critically Endangered.

The main threats to primates are due to increasing global market demands to cater to a ballooning global and African populations for palm oil for cooking foods, industry-driven deforestation, which causes habitat destruction, poaching, bush meat trade, illegal pet trade and disease. Primates, particularly the great apes, are at risk from human related diseases due to their close genetic relatedness to people. A concerted effort is needed to address these threats, through increasing the level of involvement and commitment from stakeholders.

Despite Africa being home to a third of the World's primate species, native African conservation and activism remains limited and African participation in international primate forums remains disproportionately low, primarily due to the prohibitive costs of participation. Nevertheless, greater African involvement in primate research, conservation and protection is vital for the protection of primates across the continent.

In 2020, Uganda hosted the Second Congress of the African Primatological Society (APS). Under the theme of ‘Challenges and Opportunities in Primate Conservation in Africa’, the three-day event brought together over 300 primate experts, including budding primatologists, researchers, conservationists, members of the tourism industry and policy makers from across the continent and around the world.

The meeting enabled the continent’s primatological community to discuss ways that would greater the participation of African primatologists in research, conservation and other primate related issues. Some 250 out of 312 delegates from 24 different African countries were in attendance.

“When the conference was first held in Ivory Coast, we had our first annual general meeting, and I became the Vice President of APS,” says Gladys, who served as Chairperson of the APS Conference 2019 organizing committee, “I convinced them to hold the second APS in Uganda, and became the Chairperson of the organizing committee for the 2nd APS conference, and CTPH is heading the local organizing committee.”

Uganda is the unofficial primate capital of Africa. The country is home to fifteen species of primates. Four of these are endangered: these include the mountain gorilla, chimpanzee, red colobus monkey, and golden monkey. Many of the country’s Protected Areas are also home to Blue monkeys, Olive baboons, Black and White Colobus monkeys, Red-Tailed monkeys, Grey-Cheeked Mangabey, and L'Hoest's monkey. There are also smaller nocturnal species such as the Bushbaby and the Bosman's potto, lemur-like primates said to be called “softly-softly” in some English-speaking parts of the continent.

Gladys' forthcoming book is called WALKING WITH GORILLAS: The Journey of an African Wildlife Vet. Published by Simon and Schuster, 2023


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