NIH study: Superbugs flourish, pass on drug resistance in hospital wastewater systems
Hospital plumbing plays host to many antibiotic-resistant superbugs, which can share their resistances with other bacteria they meet in the sewage systems, according to a new study.
Researchers at the National Institutes of Health Clinical Center collected samples from the pipes under the hospital’s intensive care unit, which tested positive for carbapenem-resistant plasmids, or a small molecule of DNA that is separate from bacteria’s chromosomal DNA. It’s a trend that’s likely in other hospitals, too, according to the study.
Resistant bacteria in the pipes can share those plasmids with other germs that travel in the wastewater system, passing on their drug resistance, according to the study. The study noted that scientists believe hospitals’ high use of antibiotics can lead to more superbugs in the sewers.
However, the news isn’t all bad. The NIH researchers compared the results from the plumbing to five years of data on other areas of the hospital, like sinks, computers and doorknobs. Though the pipe samples contained a significant number of the carbapenem-resistant superbugs, that trend didn’t hold true for areas that had frequent patient access.
Just 1.4% of high-touch areas tested came back positive for the bacteria, as did 11% of drains. This suggests that hospital efforts to minimize exposure to these pathogens are generally working, NIH microbiologist Karen Frank, Ph.D., M.D., co-leader of the study, said in an announcement.
“If you’re tracking resistant bacteria, you might be able to prevent more infections in patients,” Frank said.
Superbugs that are resistant to carbapenem, a last-resort antibiotic used to treat resistant infections, are among the most dangerous to human health, according to the World Health Organization. The group released a list of the 12 deadliest infections, and all three listed as “critical” are resistant to carbapenem.
Experts have warned that these bugs could be deadlier than cancer by 2050.
The central provider response to drug resistant superbugs is antibiotic stewardship, an effort backed by major groups like WHO. The most successful programs continually engage with clinicians and take advantage of tech that help monitor antibiotic use and infection rates.
The NIH researchers said the key takeaway from the study is that hospitals shouldn’t panic but instead focus more on tracking the spread of these bacteria, or the resistance-granting plasmids. By knowing where these gene-sharing bugs hide, it’s easier to keep them away from patients.
“In the big picture, the concern is the spread of these resistant organisms worldwide, and some regions of the world are not tracking the spread of the hospital isolates,” Frank said.