Patients were infected with antibiotic-resistant bacteria living in the plumbing of the National Institutes of Health’s hospital in Bethesda, Md., contributing to at least three deaths in 2016.
A study published Wednesday in the New England Journal of Medicine found that, from 2006 to 2016, at least 12 patients at the NIH Clinical Center, which provides experimental therapies and hosts research trials, were infected with Sphingomonas koreensis, an uncommon bacteria. The paper, written by NIH researchers, suggests that the infections came from contaminated water pipes, where the bacteria may have been living since as early as 2004, soon after construction of a new clinical center building.
This report is the latest instance of pathogenic contamination at the NIH, an issue that has roiled the highest ranks of the agency in recent years. The Clinical Center was the site of a superbug outbreak in 2011, and fungi were found in drug vials in 2015. After a scathing April 2016 internal report concluded that NIH researchers sometimes put patient safety at risk, Director Francis Collins replaced the top leadership at the Clinical Center.
However, infections like this are not uncommon in medical centers — the Centers for Disease Control and Prevention estimates that about 4 percent of hospital patients pick up diseases from the hospital environment.
“It is not exceptional for a hospital to have a [hospital-originating] infection,” Dr. Tara Palmore, hospital epidemiologist at the Clinical Center and one of the study’s authors, said in an interview. “They occur in every hospital.”
Wednesday’s paper is the NIH’s first broad disclosure of the Sphingomonas koreensis infections. Palmore said information about the infections was presented at a 2017 scientific meeting and at an NIH lecture that was broadcast online.
“Scientific publication is one way of many to discuss information – and always has a lag time,” she said through the spokesperson.
According to the paper, the hospital became aware of the problem in 2016, when six patients at the Clinical Center came down with similar infections over the course of six months. They were all infected with a type of Sphingomonas bacteria, which live in water. Four were infected with the drug-resistant Sphingomonas koreensis, and three of them died.
It’s unclear whether Sphingomonas koreensis is what killed those patients, who had undergone stem cell transplants, which leave patients vulnerable to infections.
“The three patients who died also had multiple other life-threatening conditions, which were complications of their underlying disease,” Palmore said.
“[Sphingomonas koreensis] are fairly weak bacteria,” she said. “But in a patient who is highly immunosuppressed, it doesn’t take a highly virulent bacteria to cause additional illness.”
The cluster of Sphingomonas infections prompted researchers to search the hospital’s water infrastructure to see where the bacteria might have been hiding out. They found Sphingomonas koreensis living in water that came out of the faucets in patient rooms, as well as inside the sink faucets themselves.
The paper details some changes that were made to the Clinical Center’s water system after the cluster was discovered, including increasing the temperature of the water and adding more chlorine. Palmore said the low chlorine level was identified and fixed in a matter of days.
She added that the staff at the Clinical Center are still experimenting with different configurations of water pipes — “literally taking out plumbing and putting it in a different shape” — in an effort to minimize the amount of bacteria that can grow in the water system.
“It’s a long-term project in our hospital that proceeds at a slow pace because we can’t turn the entire hospital into our laboratory,” Palmore said.
No new Sphingomonas koreensis infections have been reported at the Clinical Center since 2016, when the changes were made.
This story was updated with comments from Dr. Tara Palmore.