Researchers recovered a carbapenemase-producing organism from the shaft of a hospital drain auger, prompting calls for standardized reprocessing protocols and further investigation into maintenance equipment as a potential source of environmental dissemination.
Equipment used to clear hospital plumbing blockages may warrant closer attention from infection prevention teams, according to a poster presented at IDWeek in Washington, DC, held from October 21 to 24, 2026. Researchers recovered a carbapenemase-producing organism (CPO) from a drain auger, commonly called a drain snake, used in health care plumbing maintenance. The positive sample came from the device’s shaft, demonstrating contamination beyond the tip inserted into the drain.
The study, “Snakes on a Drain: Not Just the Tip of a Novel CPO Reservoir,” examined drain augers and associated attachments from 3 acute care hospitals. Investigators collected 46 individual samples from 13 augers and recovered 1 isolate of Citrobacter freundii carrying the KPC gene. The overall sample positivity rate was 2.2%.
“This is the first report identifying a CPO on a drain auger used in health care plumbing maintenance,” the researchers stated in the poster’s conclusion.
Examining Equipment Used in Hospital Drains
The researchers identified sink drains and plumbing systems as common locations for CPOs. Their investigation focused on the equipment used to maintain those systems, such as a drain auger, which is a flexible, narrow metal coil routinely used to mechanically clear blockages in sinks and pipes. The study’s objective was to determine whether these devices were colonized with CPOs.
1. A CPO was recovered from maintenance equipment. One of 46 samples from 13 drain augers was positive for C freundii carrying the KPC gene, a 2.2% sample positivity rate.
2. Contamination extended beyond the tip. The positive sample came from the auger’s shaft.
3. Further evaluation and standardized reprocessing are needed. The researchers identified drain snakes as potential vectors for CPO dissemination, without demonstrating patient transmission.
The poster illustrates how an auger passes through a sink drain to dislodge an obstruction. A separate photograph shows the coiled metal tip of a drain auger with adherent organic debris following use. These illustrations accompany the investigation of whether organisms could be recovered from the equipment itself.
Rather than sampling only the end of each device, the investigators examined multiple locations along its length. This approach allowed them to assess the distal tip, mid-shaft, and proximal end. The location of the eventual positive sample became a central finding because contamination was detected on the shaft rather than being confined to the immediate distal tip.
Sampling Across 3 Acute Care Hospitals
The team sampled augers on a random day in relation to their last use and cleaning. Cleaning practices included citrus-based cleaners. At the time of sampling, the devices had last been used a median of 5 days earlier.
Investigators used sterile 6-inch cotton-tipped applicators to swab the designated locations on each device. The swabs were placed in Oxoid Brain Heart Infusion broth for transport and enrichment. Culture and molecular testing followed to detect carbapenemase-producing organisms.
Broth cultures were incubated for a total of 5 days. The researchers noted that non-CPO organisms were not identified. The reported microbiologic findings therefore focused on the study’s objective of detecting CPOs on the sampled maintenance equipment.
Of the 46 samples collected, 1 was positive. The organism recovered was C freundii carrying the KPC gene. The poster’s summary figure identifies the positive sample location on the auger shaft, reinforcing the finding that contamination extended beyond the device’s tip. The reported 2.2% positivity rate refers to individual samples, rather than the percentage of hospitals or augers with positive findings.
A Potential Route for Environmental Dissemination
The researchers described the finding as evidence that drain snakes may represent a previously unrecognized vector for introducing CPOs into sink drains and spreading them within the hospital environment. Their conclusion identifies a potential role for the equipment, rather than reporting a demonstrated transmission event involving patients.
“This finding suggests that drain snakes may act as a previously unrecognized vector for sink-drain inoculation and environmental dissemination of CPO within hospitals,” the researchers wrote.
The poster calls for standardized reprocessing protocols for these devices. It also recommends further evaluation of maintenance equipment as potential vectors. These recommendations follow the recovery of a CPO from equipment used to clear plumbing systems already recognized as common locations for such organisms.
For infection prevention teams, the study directs attention to the tools entering hospital drains as well as the drains themselves. Its finding of shaft contamination provides a specific reason to examine the full device when considering reprocessing. The authors’ proposed next steps center on developing consistent protocols and investigating maintenance equipment more closely to better understand its potential contribution to environmental dissemination.
Poster authors: Eric Devine, MPH, CPHI(C); Susy Hota, MD, MSc; Richard Batista; Kavitha Ramaraj, RN, BSN; Krista Marquis, MLT; Beata Mostowiak; Kevin Bell, AMRT, FSRT; Qasim Mohiuddin, MScHQ, RN; and Alon Vaisman, MD, MAS.
Affiliation: Infection Prevention and Control, University Health Network, Toronto.
