“Hospital’s Water Purification System Stripped out Chlorine, Killing 3 Patients: It Was Supposed to Improve Taste, but Instead Led to Deadly Infections”, 2023-03-07 ():
Water purification systems installed in two ice machines in a Boston hospital were supposed to make the water taste and smell better for patients on a surgery floor—but it ended up killing 3 of them, an investigation found…Researchers detailed the case cluster and ensuing investigation in a study published Monday in the Annals of Internal Medicine.
…Identifying the cluster and the culprit took some sleuthing; the 4 cases occurred sporadically between March 2017 and October 2018 at Brigham and Women’s Hospital in Boston. And it wasn’t immediately obvious that they were linked.
…Whole genome sequencing of clinical isolates from the 4 identified cases revealed almost perfect matches of their M. abscessus isolates. The bacterial isolates’ genomes had just 3 different point mutations among them; fewer than 20 suggest an epidemiological link. So, the researchers got to work trying to find a common source.
…The most obvious similarity between the patients’ stays was that they were all prolonged. While the mean length of stay for similar patients in the cardiac surgery floor was just over two weeks, the 4 patients had stays between 42 days and 131 days before their M. abscessus were identified. And nurses anecdotally noted that the patients seemed to consume more ice than others.
…M. abscessus is a water-loving bacterium known to occur at low levels in tap water, which is not sterile. As such, the researchers turned to the hospital’s water sources, surveying sinks, showers, and ice and water machines on the floor…And from those samples, the researchers could fish out genetic sequences unique to the M. abscessus isolates that had infected the patients, strongly suggesting this was the common source.