‘Potential to Spark a Global Pandemic’: Wild Animals in Botswana Found Resistant to Antibiotics
Banded mongooses don’t get the love like their celebrated cousins the meerkats. Their eyes aren’t quite as soulful, and they don’t spend as much time standing around on their hind legs looking human. Even so, these small, highly social creatures are a favorite with visitors to sub-Saharan Africa, nosing around the camp in small groups, searching for beetles, millipedes, and other choice foods. But now, improbably, banded mongooses have turned up in the middle of a global health crisis.
It is, on the surface, a familiar story about the greatest miracle drugs in modern medicine: Massive overuse of antibiotics has rapidly caused bacteria to develop resistance, meaning that many human illnesses, from a common urinary tract infection to tuberculosis, are becoming difficult or impossible to treat. Antibiotic resistance is so widespread that, according to new research, it occurs even in wildlife living in a national park in southern Africa.
The new study, published last week in the scientific journal EcoHealth, raises questions about overuse of antibiotics, the hidden costs of ecotourism, and the need for more careful management of protected wildlife areas. Diseases spilling over from animals to humans have “the potential to spark a global pandemic,” according to the authors, and the new data add the alarming prospect that some emerging pathogen—the next SARS or swine flu—may be resistant to antibiotic treatment from Day One.
Banded mongoose troops at Chobe National Park, near Botswana’s northern border with Zambia and Zimbabwe, are the subject of the study. For the past dozen years, a Virginia Tech team, led by wildlife researcher Kathleen Alexander, has been following the mongoose population there, as a model for understanding the pathways diseases follow as they pass back and forth between humans and animals.
Alexander first got interested in the banded mongoose while she was raising two children and working as a veterinarian for Botswana’s Department of Wildlife and National Parks. One day at Chobe, she saw two visibly sick mongooses stagger directly through the sand pit where her children played. “I thought, ‘Oh, gosh, rabies,’ ” she says.
Instead, Alexander discovered that the sick animals were suffering from the first new tuberculosis pathogen identified in almost a quarter-century. She still doesn’t know whether this particular tuberculosis strain can infect humans, or what the reservoir species is in the natural world (the mongooses are just carriers). But because Botswana’s human population already has among the highest infection rates in the world for both HIV and tuberculosis, the new pathogen was an obvious source of concern. Alexander’s team also discovered that the mongooses carry leptospirosis, which can be fatal to humans without the standard antibiotic treatment.
For the new study, the researchers sampled the common intestinal bacteria E. coli in both human and mongoose fecal samples at Chobe, and found antibiotic resistance in 80 percent of the human samples and 57 percent of the mongoose samples. In one troop, says Alexander, “we found that at least one mongoose was resistant to every single antibiotic we tested, and that’s ten,” including ampicillin, tetracycline, streptomycin, and doxycycline. Resistance to three or more drugs was common, and “one individual [mongoose] had resistance to six different antibiotics.” Sewage from tourist facilities and local villages was the probable source of transmission. Mongooses frequently feed on insects around fecal wastes, and the resistant strains in human and animal samples were genetically almost identical.
Surprisingly, some of the animals were also resistant to ceftiofur, an antibiotic that’s heavily used in poultry production but not in human medicine. “This is a national park and there are no commercial poultry or livestock production systems nearby,” says Alexander. The researchers eventually discovered, however, that kitchen staff were sometimes feeding the mongooses raw chicken wastes, apparently contaminated with ceftiofur-resistant bacteria from the factory. It’s also possible, says Alexander, that humans eating improperly cooked chicken passed on the ceftiofur resistance in their wastes.
“The fact that wildlife have been exposed, and have multi-drug resistance, and in fact are resistant to every drug that we tested is frightening,” says Alexander. Other recent studies have demonstrated that humans can fatally infect mountain gorillas with respiratory pathogens and elephants with tuberculosis. The new evidence that humans can also pass on antibiotic resistance has implications for a broad range of wildlife, because mongoose is a common prey species for African wild dogs, leopards, lions, birds of prey, and many other species.
In the other direction, humans can pick up antibiotic-resistant disease when consuming bushmeat or drinking water contaminated by animal droppings. As pathogens and antibiotic resistance circulate and amplify through the landscape, cycling back and forth among different species, the implications for human health are alarming. In Botswana itself, it is essential to have antibiotics that actually work, says Alexander, because so many people already have HIV-weakened immune systems. Problems with antibiotic resistance are also rapidly spreading worldwide. Tuberculosis has once again become a global epidemic, and multi-drug resistant tuberculosis now kills 150,000 people a year. E. coli infections kill more than 800,000—and resistant strains are increasingly common.
The World Health Organization recently warned that we are on the brink of a “post antibiotic era,” and British health officials have categorized worsening antibiotic resistance as an “apocalyptic scenario” on par with a catastrophic terrorist attack.
As human populations continue to expand, says Alexander, it is increasingly urgent to recognize the intimate connection between human and animal health, and think about these things “as we plan how we use landscapes, and how we conduct ecotourism, and what we do with animals.” The study urges protected natural areas to take the obvious precautions: Make waste receptacles wildlife-proof, require closed sewage systems, and prohibit staff, as well as tourists, from feeding animals. But the larger problem—rampant overuse of antibiotics in medicine and in livestock production—remains to be resolved.
The mongooses are merely the latest victims.
Richard Conniff is the author of seven books, including his latest, The Species Seekers: Heroes, Fools, and the Mad Pursuit of Life on Earth. He has won a National Magazine Award, a Gerald Loeb Award, and a 2007 Guggenheim Fellowship. His articles have appeared in Time, Smithsonian, The Atlantic, The New York Times Magazine, National Geographic, and other publications. He has written and presented television shows for networks including the National Geographic Channel, TBS, and the BBC. TakePart.com