Klebsiella Cases Tied to Handwashing Sinks

Klebsiella oxytoca is primarily a healthcare-associated pathogen acquired from environmental sources and should be on the radar of infection preventionists and environmental services professionals. Christopher Lowe, of the University of Toronto, and colleagues, report on an outbreak of class A extended-spectrum -lactamaseproducing K. oxytoca that occurred at a 472-bed, acute tertiary-care facility in Toronto.

Klebsiella oxytoca is an opportunistic pathogen that causes primarily hospital-acquired infections, most often involving immunocompromised patients or those requiring intensive care. Reported outbreaks have most frequently involved environmental sources. K. oxytoca, like other Enterobacteriaceae, may acquire extended-spectrum -lactamases (ESBL) and carbapenemases; outbreaks of multidrug-resistant K. oxytoca infection pose an increasing risk to hospitalized patients.

From October 2006 through March 2011, a total of 66 patients acquired K. oxytoca with one of two related pulsed-field gel electrophoresis patterns. Isolates were considered hospital acquired if the first specimen (clinical culture or rectal swab) yielding resistant K. oxytoca was obtained >3 days after the admission date or if the specimen was obtained <3 days after admission in a patient who had been hospitalized at the outbreak hospital within the previous three months. Patients were characterized as infected or colonized on the basis of National Healthcare Safety Network definitions.

New cases continued to occur despite reinforcement of infection control practices, prevalence screening, and contact precautions for colonized/infected patients. Cultures from handwashing sinks in the intensive care unit yielded K. oxytoca with identical pulsed-field gel electrophoresis patterns to cultures from the clinical cases. No infections occurred after implementation of sink cleaning three times daily, as well as sink drain modifications, and an antimicrobial stewardship program. In contrast, a cluster of four patients infected with K. oxytoca in a geographically distant medical ward without contaminated sinks was contained with implementation of active screening and contact precautions.

The researchers emphasize that sinks should be considered potential reservoirs for clusters of infection caused by K. oxytoca. Their research was published in the August 2012 issue of Emerging Infectious Diseases.

Reference: Lowe C, Willey B, et al. Outbreak of Extended-Spectrum -Lactamaseproducing Klebsiella oxytoca Infections Associated with Contaminated Handwashing Sinks. Vol. 18, No. 8. Emerg Infect Dis. August 2012.