Wastewater drains: epidemiology and interventions in 23 carbapenem-resistant organism outbreaks

Abstract

For many years, patient-area wastewater drains (ie, sink and shower drains) have been considered a potential source of bacterial pathogens that can be transmitted to patients. Recently, evolving genomic epidemiology tools combined with new insights into the ecology of wastewater drain (WWD) biofilm have provided new perspectives on the clinical relevance and hospital-associated infection (HAI) transmission risks related to these fixtures. To further clarify the clinical relevance of WWD-associated pathogen transmission, reports of outbreaks attributed to WWDs were selected for review that (1) investigated the outbreak epidemiology of WWD-associated transmission of bacterial pathogens, (2) utilized advanced microbiologic methods to establish clonality of outbreak pathogens and/or resistance genes, or (3) described interventions implemented to mitigate transmission of the outbreak pathogens from WWDs. These reports were collated, compared, and analyzed, and the results are presented here.

A Large, Refractory Nosocomial Outbreak of Klebsiella pneumoniae Carbapenemase-Producing Escherichia coli Demonstrates Carbapenemase Gene Outbreaks Involving Sink Sites Require Novel Approaches to Infection Control

“…Our experience highlights the limited evidence for managing large CRE outbreaks, including environmental sampling protocols and interventions, despite numerous centers reporting similar experiences with wastewater sites acting as CRE reservoirs (18,(20)(21)(22)(23). Widespread colonization with KPC-producing E. coli is a concern, as E. coli is a common gastrointestinal colonizer and cause of infection, and any stable association between bla KPC and E. coli, particularly in pathogenic lineages such as ST131 (Fig.…”

Contamination of Hospital Plumbing

“…However, on returning to standard disinfection protocols, CP-PA regrowth was observed, which is consistent with findings from other studies that have reported challenges in achieving sustained decontamination of plumbing. 3 A major strength of this work was its use of WGS to demonstrate that environmental contamination across the ward was likely mediated by introduction of P aeruginosa into a single drain. This result highlights how contamination of sink and shower drains can propagate to proximate rooms via plumbing, and illuminates an epidemiologic signature that may be associated with plumbing-mediated outbreaks.…”

Genomic surveillance of Escherichia coli and Klebsiella spp. in hospital sink drains and patients

“…In conclusion, without conditioning on the presence of resistance markers, we have demonstrated that colonization of ward sink drains with diverse and abundant populations of Enterobacterales, including drug-resistant lineages, is common and persistent. The evidence linking contaminated, unmitigated wastewater reservoirs (including sink drains) in healthcare settings with outbreaks of colonization/disease with drug-resistant Gram-negative bacilli in patients seems clear [5, 45], but no study to our knowledge has focused on the potential risk posed by Enterobacterales in sinks in general. Screening of sinks is not carried out in the absence of observed outbreaks, making it difficult to quantify wider patient-associated risk from the studies available.…”