Researchers investigating how multidrug-resistant bacteria can potentially spread from hospital sinks to patients found that bacteria in sinks initially colonize in the elbows and slowly spread to the strainers and subsequently splatter to the bowl and surrounding areas. The researchers said that their findings could have implications for infection control interventions and future plumbing designs in eliminating this mode of transmission among vulnerable patients.
“Many recent reports demonstrate that sink drain pipes become colonized with highly consequential multidrug-resistant bacteria, which then result in hospital-acquired infections. However, the mechanism of dispersal of bacteria from the sink to patients has not been fully elucidated,” Amy J. Mathers, MD, associate professor of medicine and pathology in the Division of Infectious Diseases and International Health at the University of Virginia Health System, and colleagues wrote in Applied and Environmental Microbiology. “This work helps to more clearly define the mechanism and risk of transmission from a wastewater source to hospitalized patients in a world with increasingly antibiotic-resistant bacteria, which can thrive in wastewater environments and cause infections in vulnerable patients.”
The researchers designed a laboratory containing five sinks modeled after the most common ICU hand-washing station in the acute care hospital at their facility to study the spread of green fluorescent protein-expressing Escherichia coli. Mathers said in a press release that it is the first laboratory of its kind that the research team is aware of in the U.S.
During the investigation, the bacteria spread through a staged mode of transmission from the lower pipe to the sink strainer, then subsequently spread to the bowl and surrounding areas. The bacteria grew at a rate of roughly 1 inch per day. According to Mathers, it takes approximately 1 week for the bacteria to reach the sink strainers. From there, bacteria can splash around the sink and onto surroundings areas where they can be transmitted to patients.
Mathers and colleagues will conduct a follow-up study with the CDC to further investigate how the pathogens reach patients, the release said.
“This type of foundational research is needed to understand how these bacteria are transmitted so that we can develop and test potential intervention strategies that can be used to prevent further spread,” Mathers said. – by Stephanie Viguers
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