Overuse of antibiotics threatens wild chimpanzees

Wild chimpanzees at Gombe National Park in Tanzania are greatly affected by human antibiotic consumption. In a recent study, nearly half of all fecal samples collected from the chimpanzees were found to contain bacteria that is resistant to a major class of antibiotics.

Study lead author Thomas Gillespie is an associate professor in the Department of Environmental Sciences and Rollins School of Public Health at Emory University.

“Our results suggest that the antibiotic-resistant bacteria is actually spreading from people to non-human primates by making its way into the local watershed,” said Professor Gillespie.

“People are bathing and washing in the streams, contaminating the water with drug-resistant bacteria where wild chimpanzees and baboons drink.”

The researchers were specifically looking for resistance to drugs called sulfonamides, which are often used by people in the region to treat diarrheal diseases.

The team tested fecal samples from humans, domestic animals, chimpanzees, and baboons in and around Gombe National Park, as well as the stream water used by these groups.

Overall, sulfonamide resistance appeared in 74 percent of the human samples, 48 percent of chimpanzee samples, 34 percent of baboon samples, and 17 percent of the domestic animal samples. Traces of the drug were detected in 19 percent of the samples taken from local streams.

Professor Gillespie is a disease ecologist who helped pioneer the “One Health” approach to protecting humans, ecosystems, and biodiversity. In collaboration with the Jane Goodall Institute in Tanzania, Professor Gillespie works on projects to help farmers co-exist with primates and other wildlife in ways that minimize the risk of pathogen exchange between species. HIV, the virus that causes AIDS, spilled over from chimpanzees to people.

“It’s important to consider both sides of the story – human health and well-being, as well as conservation of chimpanzees and other species,” said Professor Gillespie.

The number of chimpanzees in Gombe National Park is down to about 95. The population has been hit hard by disease and habitat fragmentation.

Diarrheal diseases are common in the region, and people often use cheap sulfonamide antibiotics that are available without a prescription. 

“The majority of people in our sampling harbored bacteria resistant to the sulfonamide medication they are taking,” said Professor Gillespie. “In those cases, they’re spending their money on a drug that is not helping them get better. Overuse of such drugs creates the potential for more lethal, antibiotic-resistant ‘super bugs’ to emerge.”

More local guidance is needed on the proper use of antibiotics, said Professor Gillespie. He noted that it is also important to improve hygiene for wash-related activities in area streams, as well as to improve disposal of human waste materials.

“By misusing antibiotics, people can actually harm not only themselves, but also the species they share an environment with. After drug-resistant bacteria jump into chimpanzees, it can further evolve with the chimpanzees and then spill back into humans.” 

“We need to be thinking about infectious diseases within evolutionary and ecological frameworks, something that’s not often done in medicine.”

The study is published in the journal Pathogens.

–—

By Chrissy Sexton, Earth.com Staff Writer