Sinks in patient rooms in ICUs are associated with higher rates of hospital-acquired infection: a retrospective analysis of 552 ICUs

Biofilms, mobile genetic elements and the persistence of pathogens on environmental surfaces in healthcare and food processing environments

Biofilms are the natural state for bacterial and fungal species. To achieve surface hygiene in commercial facilities, the presence of biofilms must be adequately considered. However, standard disinfectant and sanitizer efficacy tests required by the US-EPA and the European Committee for Standardization (CEN) do not currently consider the role of environmental biofilms. This selective review will discuss what biofilms are and why they are important. We will also cover where they are commonly found in healthcare and food processing facilities and explore how current antimicrobial test methods required for product registration do not test for the presence of biofilms. Additionally, we will explore how a lack of efficacy against biofilms may play a role in the development of antimicrobial resistance in healthcare facilities due to the exchange of mobile genetic elements that occur readily in a biofilm matrix.

The impact of sink removal and other water-free interventions in intensive care units on water-borne healthcare-associated infections: A systematic review

BACKGROUND

With increasing awareness of water sinks as potential sources of outbreaks and transmission of multi-drug resistant (MDR) bacteria in intensive care units (ICUs), there is growing interest in water-free patient care systems. This systematic review reviewed and synthesized available evidence on the effectiveness of sink removal with or without water-free activities in the ICU environment to reduce water-borne healthcare-associated infections.

METHODS

We searched five databases (PubMed, MEDLINE, Scopus, Web of Science and Embase) for studies published from 1st January 1980 to 2nd April 2024 that examined water-less or water-free activities in the ICU to reduce healthcare-associated infections and patient colonization.

RESULTS

Of 2,075 articles, seven quasi-experimental studies (total: 332 patient beds) met the study selection criteria. 6/7 studies (85.7%) were based in adult ICUs; one (14%) was in a neonatal ICU. 5/7 sites (71.4%) implemented water-less interventions after an outbreak. Water-free alternatives used included water-less bath products (6/7;85.7%), bottled water for consumption (3/7;42.9%), oral care (3/7;42.9%) and dissolving of oral medication (4/7;57.1%), designated 'contaminated' sink outside of patient and medication preparation areas for disposal of wastewater (4/7; 57.1%). Implicated pathogens studied included MDR gram-negative bacteria (4/7; 57.1%), MDR Pseudomonas aeruginosa only (2/7; 28.6%), and pulmonary non-tuberculous mycobacterium (NTB) (1/7; 14.3%). 5/7 (71.4%) studies reported outbreak cessation.

CONCLUSION

Preliminary evidence, from a limited number of studies of which the majority were conducted in an outbreak setting, suggest that sink removal and other water-free interventions in the ICU helped terminate outbreaks involving taps and decrease hospital-onset respiratory isolation of pulmonary NTB.

Sink interventions in the ICU to reduce risk of infection or colonization with Gram-negative pathogens: a systematic review of the literature

BACKGROUND

Healthcare-associated infections (HAIs) are a major problem in intensive care units (ICUs). The hospital water environment is a potential reservoir for Gram-negative bacteria (GNB), and it has been shown that contaminated sinks contribute to the spread of GNB in outbreak and non-outbreak settings. This study aimed to investigate which sink interventions may reduce GNB infection and colonization rates in the ICU.

METHODS

A database search (MEDLINE via PubMed, EMBASE via Ovid and ClinicalTrials.gov) was undertaken without restrictions on language or date of publication. Studies of any design were included if they described an intervention on the water fixtures in patient rooms, and presented data about HAI or colonization rates in non-outbreak settings. Acquisition (infection and/or colonization) rates of GNB and Pseudomonas aeruginosa were analysed as outcomes.

RESULTS

In total, 4404 records were identified. Eleven articles were included in the final analysis. No randomized controlled trials were included in the analysis, and all studies were reported to have moderate to serious risk of bias. Removing sinks and applying filters on taps had a significant impact on GNB acquisition, but there was high heterogeneity among reported outcomes and sample size among the studies.

CONCLUSION

Few studies have investigated the association of sinks in patient rooms with healthcare-associated acquisition of GNB in non-outbreak settings. Heterogeneity in study design made it impossible to generalize the results. Prospective trials are needed to further investigate whether removing sinks from patient rooms can reduce the endemic rate of HAIs in the ICU.

Long-term intensive care unit outbreak of carbapenemase-producing organisms associated with contaminated sink drains

BACKGROUND

Between 2018 and 2022, a Belgian tertiary care hospital faced a growing issue with acquiring carbapenemase-producing organisms (CPO), mainly VIM-producing P. aeruginosa (PA-VIM) and NDM-producing Enterobacterales (CPE-NDM) among hospitalized patients in the adult intensive care unit (ICU).

AIM

To investigate this ICU long-term CPO outbreak involving multiple species and a persistent environmental reservoir.

METHODS

Active case finding, environmental sampling, whole-genome sequencing (WGS) analysis of patient and environmental strains, and implemented control strategies were described in this study.

FINDINGS

From 2018 to 2022, 37 patients became colonized or infected with PA-VIM and/or CPE-NDM during their ICU stay. WGS confirmed the epidemiological link between clinical and environmental strains collected from the sink drains with clonal strain dissemination and horizontal gene transfer mediated by plasmid conjugation and/or transposon jumps. Environmental disinfection by quaternary ammonium-based disinfectant and replacement of contaminated equipment failed to eradicate environmental sources. Interestingly, efflux pump genes conferring resistance to quaternary ammonium compounds were widespread in the isolates. As removing sinks was not feasible, a combination of a foaming product degrading the biofilm and foaming disinfectant based on peracetic acid and hydrogen peroxide has been evaluated and has so far prevented recolonization of the proximal sink drain by CPO.

CONCLUSION

The persistence in the hospital environment of antibiotic- and disinfectant-resistant bacteria with the ability to transfer mobile genetic elements poses a serious threat to ICU patients with a risk of shifting towards an endemicity scenario. Innovative strategies are needed to address persistent environmental reservoirs and prevent CPO transmission.