Shower Drains Research Articles

Comment on the the Court of Appeal of Antwerp’s Decision in “Photos of Shower Drains”

Comment on the the Court of Appeal of Antwerp’s Decision in “Photos of Shower Drains”

Containment of a KPC-CRE Outbreak Associated with Premise Plumbing in a Long-Term Care Facility— Minnesota, 2022-2023

Background: On March 23, 2022, the Minnesota Department of Health (MDH) was notified of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella oxytoca isolated from a resident’s urine in long-term care facility A (LTCF-A). Carbapenem-resistant Enterobacterales (CRE) are reportable statewide with required isolate submission to MDH Public Health Laboratory (MDH-PHL), where carbapenemase production and mechanism identification is confirmed. Methods: MDH partnered with LTCF-A on a containment response, including infection prevention and control (IPC) measures, KPC-CRE education, and colonization screening. Rectal swabs were screened for carbapenemase genes by real-time PCR (Cepheid Xpert Carba-R), with positive specimens undergoing culture, isolation, and whole genome sequencing (WGS). MDH-PHL conducted WGS including multilocus sequence typing (MLST) and single nucleotide polymorphism (SNP) analysis to describe genetic relationships among isolates. When screening indicated a potential environmental source, due to species diversity and ongoing resident transmission, an environmental screening plan was developed including collection of premise plumbing samples from room faucets, aerators, sinks, toilets, and shared shower drains. Results: KPC-CRE was detected in 23 residents (urine, n=2; rectal swab, n=21) during March 2022–November 2023. 21 isolates comprising 10 Enterobacterales species were cultured from KPC-positive screening specimens. SNP analysis performed on bacteria of the same species demonstrated 5 distinct clusters of relatedness comprising 2-3 residents per cluster (Cluster 1: Klebsiella oxytoca, n=3; Cluster 2: Klebsiella oxytoca, n=3; Cluster 3: Escherichia coli, n=2; Cluster 4: Klebsiella pneumoniae, n=2; Cluster 5: Raoultella planticola, n=2). 7 KPC-positive resident specimens did not yield a culturable organism. KPC-CRE was detected throughout the premise plumbing including 8 of 9 shared shower room drains and 6 of 75 resident room sink drains. WGS and SNP analysis suggest relatedness among resident and environmental KPC-CRE isolates. Gaps in IPC measures including hand hygiene, use of personal protective equipment (PPE), environmental cleaning and disinfection, and sink hygiene practices were observed during onsite assessments. Use of an EPA-registered biofilm disinfectant in facility drains and repeated environmental sampling has demonstrated a decrease in KPC-harboring bacteria within the premise plumbing, but not complete elimination. Conclusion: Containing the spread of KPC-CRE within LTCF-A has been challenging due to environmental reservoirs of KPC-CRE along with insufficient implementation of IPC practices. Continued colonization screening has been necessary to detect newly colonized residents and reinforce efforts to increase IPC compliance. Strict implementation and adherence to IPC measures, including those that minimize the spread of KPC-CRE from facility premise plumbing, are needed to fully halt KPC-CRE transmission within LTCF-A.

Sanitary installations and wastewater plumbing as reservoir for the long-term circulation and transmission of carbapenemase producing Citrobacter freundii clones in a hospital setting

BackgroundAccumulating evidence shows a role of the hospital wastewater system in the spread of multidrug-resistant organisms, such as carbapenemase producing Enterobacterales (CPE). Several sequential outbreaks of CPE on the geriatric ward of the Ghent University hospital have led to an outbreak investigation. Focusing on OXA-48 producing Citrobacter freundii, the most prevalent species, we aimed to track clonal relatedness using whole genome sequencing (WGS). By exploring transmission routes we wanted to improve understanding and (re)introduce targeted preventive measures.MethodsEnvironmental screening (toilet water, sink and shower drains) was performed between 2017 and 2021. A retrospective selection was made of 53 Citrobacter freundii screening isolates (30 patients and 23 environmental samples). DNA from frozen bacterial isolates was extracted and prepped for shotgun WGS. Core genome multilocus sequence typing was performed with an in-house developed scheme using 3,004 loci.ResultsThe CPE positivity rate of environmental screening samples was 19.0% (73/385). Highest percentages were found in the shower drain samples (38.2%) and the toilet water samples (25.0%). Sink drain samples showed least CPE positivity (3.3%). The WGS data revealed long-term co-existence of three patient sample derived C. freundii clusters. The biggest cluster (ST22) connects 12 patients and 8 environmental isolates taken between 2018 and 2021 spread across the ward. In an overlapping period, another cluster (ST170) links eight patients and four toilet water isolates connected to the same room. The third C. freundii cluster (ST421) connects two patients hospitalised in the same room but over a period of one and a half year. Additional sampling in 2022 revealed clonal isolates linked to the two largest clusters (ST22, ST170) in the wastewater collection pipes connecting the rooms.ConclusionsOur findings suggest long-term circulation and transmission of carbapenemase producing C. freundii clones in hospital sanitary installations despite surveillance, daily cleaning and intermittent disinfection protocols. We propose a role for the wastewater drainage system in the spread within and between rooms and for the sanitary installations in the indirect transmission via bioaerosol plumes. To tackle this problem, a multidisciplinary approach is necessary including careful design and maintenance of the plumbing system.

Enhanced monitoring of healthcare shower water in augmented and non-augmented care wards showing persistence of Pseudomonas aeruginosa despite remediation work.

Introduction. Pseudomonas aeruginosa in healthcare shower waters presents a high risk of infection to immune-suppressed patients; identifying the colonization-status of water outlets is essential in preventing acquisition.Hypothesis/Gap Statement. Testing frequencies may be insufficient to capture presence/absence of contamination in healthcare waters between sampling and remediation activities. Standardization of outlets may facilitate the management and control of P. aeruginosa.Aim. This study aims to monitor shower waters and drains for P. aeruginosa in augmented and non-augmented healthcare settings every 2 weeks for a period of 7 months during remedial actions.Methodology. All shower facilities were standardized to include antimicrobial silver-impregnated showerhead/hose units, hose-length fixed to 0.8 m and replaced every 3 months. Standard hospital manual decontamination/disinfection occurred daily. Thermostatic-mixer-valves (TMVs) were replaced and disinfected if standard remediation unsuccessful.Results. Of 560 shower and drain samples collected over 14 time-points covering 7 months, P. aeruginosa colonized 40 %(4/10; non-augmented) and 80 %(8/10; augmented-care) showers in the first week. For each week elapsed, new outlets became contaminated with P. aeruginosa by 18-19 % (P<0.001) in shower waters (OR=1.19; CI=1.09-1.31) and drains (OR=1.18; CI=1.09-1.30). P. aeruginosa occurrence in shower water was associated with subsequent colonization of the corresponding drain and vice versa (chi-square; P<0.001) with simultaneous contamination present in 31 %(87/280) of areas. TMV replacement was ineffective in eradicating colonisation in ~83 % of a subset (6/20; three per ward) of contaminated showers.Conclusions. We demonstrate the difficulties in eradicating P. aeruginosa from hospital plumbing, particularly when contamination is no longer sporadic. Non-augmented care settings are reservoirs of P. aeruginosa and should not be overlooked in outbreak investigations. Antimicrobial-impregnated materials may be ineffective once colonization with P. aeruginosa is established beyond the hose and head. Reducing hose-length insufficient to prevent cross-contamination from shower drains. P. aeruginosa colonization can be transient in both drain and shower hose/head. Frequent microbiological monitoring suggests testing frequencies following HTM04-01 guidelines are insufficient to capture the colonization-status of healthcare waters between samples. Disinfection/decontamination is recommended to minimize bioburden and the effect of remediation should be verified with microbiological monitoring. Where standard remediation did not remove P. aeruginosa contamination, intensive monitoring supported justifying replacement of showers and contiguous plumbing.

Genomic Investigation and Successful Containment of an Intermittent Common Source Outbreak of OXA-48-Producing Enterobacter cloacae Related to Hospital Shower Drains.

ABSTRACTThe hospital environment has been reported as a source of transmission events and outbreaks of carbapenemase-producing Enterobacterales. Interconnected plumbing systems and the microbial diversity in these reservoirs pose a challenge for outbreak investigation and control. A total of 133 clinical and environmental OXA-48-producing Enterobacter cloacae isolates collected between 2015 and 2021 were characterized by whole-genome sequencing (WGS) to investigate a prolonged intermittent outbreak involving 41 patients in the hematological unit. A mock-shower experiment was performed to investigate the possible acquisition route. WGS indicated the hospital water environmental reservoir as the most likely source of the outbreak. The lack of diversity of the blaOXA-48-like harbouring plasmids was a challenge for data interpretation. The detection of blaOXA-48-like-harboring E. cloacae strains in the shower area after the mock-shower experiment provided strong evidence that showering is the most likely route of acquisition. Initially, in 20 out of 38 patient rooms, wastewater traps and drains were contaminated with OXA-48-positive E. cloacae. Continuous decontamination using 25% acetic acid three times weekly was effective in reducing the trap/drain positivity in monthly environmental screening but not in reducing new acquisitions. However, the installation of removable custom-made shower tubs did prevent new acquisitions over a subsequent 12-month observation period. In the present study, continuous decontamination was effective in reducing the bacterial burden in the nosocomial reservoirs but was not sufficient to prevent environment-to-patient transmission in the long term. Construction interventions may be necessary for successful infection prevention and control.IMPORTANCE The hospital water environment can be a reservoir for a multiward outbreak, leading to acquisitions or transmissions of multidrug-resistant organisms in a hospital setting. The majority of Gram-negative bacteria are able to build biofilms and persist in the hospital plumbing system over a long period of time. The elimination of the reservoir is essential to prevent further transmission and spread, but proposed decontamination regimens, e.g., using acetic acid, can only suppress but not fully eliminate the environmental reservoir. In this study, we demonstrated that colonization with multidrug-resistant organisms can be acquired by showering in showers with contaminated water traps and drains. A construction intervention by installing removable and autoclavable shower inserts to avoid sink contact during showering was effective in containing this outbreak and may be a viable alternative infection prevention and control measure in outbreak situations involving contaminated shower drains and water traps.

Molecular epidemiology of an extended multiple-species OXA-48 CPE outbreak in a hospital ward in Ireland, 2018-2019.

Molecular epidemiological description of an OXA-48 CPE outbreak affecting a tertiary-care hospital ward in Ireland over an extended period (2018-2019). Microbiological testing and whole-genome sequencing (WGS) were performed on all 56 positive OXA-48 outbreak case isolates. In total, 7 different species were identified: Enterobacter hormaechei (n = 35, 62.5%), Escherichia coli (n = 12, 21.4%), Klebsiella pneumoniae (n = 5, 8.9%), Klebsiella oxytoca (n = 1, 1.8%), Klebsiella michiganensis (n = 1, 1.8%), Citrobacter freundii (n = 1, 1.8%), and Serratia marcesens (n = 1, 1.8%). E. hormaechei ST78 was the most common genotype (n = 14, 25%). Two major pOXA-48 plasmid types were identified throughout the outbreak, 'types' 1 and 2, and 5 major E. hormaechei clonal groupings were identified: ST78, ST108, ST1126, ST135, and ST66. Within each of the ST108, ST1126, ST135 and ST66 groups, the pOXA-48 harbored within each isolate were the same. Within ST78, 9 isolates contained the pOXA48 'type 2' plasmid and 5 contained the 'type 1' plasmid. Environmental specimens were taken from different outbreak ward locations: handwash basins, sink and shower drains, and taps. Of 394 environmental specimens, OXA-48 CPE was isolated from 26 (6.6%). This prolonged outbreak of OXA-48 CPE was confined to one ward, but it exemplifies the complexity and difficulty in the control of these organisms. With multiple species and genotypes involved, they may be better described as 'plasmid outbreaks.' WGS provided insights into this diversity and potential transmission among cases, though its usefulness would be enhanced by analysis as close as possible to real time so that interventions can be implemented as soon as data are available.

The Household Resistome: Frequency of β-Lactamases, Class 1 Integrons, and Antibiotic-Resistant Bacteria in the Domestic Environment and Their Reduction during Automated Dishwashing and Laundering.

Households provide a habitat for bacteria originating from humans, animals, foods, contaminated clothes, or other sources. Thus, bacteria carrying antibiotic resistance genes (ARGs) may be introduced via household members, animals, or the water supply from external habitats into private households and vice versa. Since data on antibiotic resistance (ABR) in the domestic environment are limited, this study aimed to determine the abundance of β-lactamase, mobile colistin resistance, and class 1 integron genes and the correlation of their presence and to characterize phenotypically resistant strains in 54 private households in Germany. Additionally, the persistence of antibiotic-resistant bacteria during automated dishwashing compared to that during laundering was assessed. Shower drains, washing machines, and dishwashers were sampled and analyzed using quantitative real-time PCR. Resistant strains were isolated, followed by identification and antibiotic susceptibility testing using a Vitek 2 system. The results showed a significantly higher relative ARG abundance of 0.2367 ARG copies/16S rRNA gene copies in shower drains than in dishwashers (0.1329 ARG copies/16S rRNA gene copies) and washing machines (0.0006 ARG copies/16S rRNA gene copies). blaCMY-2, blaACT/MIR, and blaOXA-48 were the most prevalent ARG, and intI1 occurred in 96.3% of the households, while no mcr genes were detected. Several β-lactamase genes co-occurred, and the resistance of bacterial isolates correlated positively with genotypic resistance, with carbapenemase genes dominating across isolates. Antibiotic-resistant bacteria were significantly reduced during automated dishwashing as well as laundering tests and did not differ from susceptible strains. Overall, the domestic environment may represent a potential reservoir of β-lactamase genes and β-lactam-resistant bacteria, with shower drains being the dominant source of ABR.IMPORTANCE The abundance of antibiotic-resistant bacteria and ARGs is steadily increasing and has been comprehensively analyzed in natural environments, animals, foods, and wastewater treatment plants. In this respect, β-lactams and colistin are of particular interest due to the emergence of multidrug-resistant Gram-negative bacteria. Despite the connection of private households to these environments, only a few studies have focused on the domestic environment so far. Therefore, the present study further investigated the occurrence of ARGs and antibiotic-resistant bacteria in shower drains, washing machines, and dishwashers. The analysis of the domestic environment as a potential reservoir of resistant bacteria is crucial to determine whether households contribute to the spread of ABR or may be a habitat where resistant bacteria from the natural environment, humans, food, or water are selected due to the use of detergents, antimicrobial products, and antibiotics. Furthermore, ABR could limit the options for the treatment of infections arising in the domestic environment.

Role of the Environment in Transmission of Multiresistant Enterobacter cloacae in a Hematology-Oncology Department

Background: The patient environment is increasingly considered a major source of transmission of nosocomial bacteria to patients. In May 2019, a cluster of 3 patients with multiresistant Enterobacter cloacae was discovered in the hematology-oncology department of the Maastricht University Medical Center (built in 1991). The strains had an identical antibiogram: ESBL-positive, ciprofloxacin R, cotrimoxazole R, meropenem S, and colistin S. One neutropenic patient had a positive blood culture for this strain, resistant to the empiric treatment with piperacillin-tazobactam, but the patient recovered after switching the antibiotic regimen to meropenem. All strains were determined to be identical by amplified-fragment length polymorphism and whole-genome multi-locus sequencing typing (genotype A). New cases occurred, despite the introduction of contact isolation of positive and contact patients. Therefore, weekly point-prevalence screening was introduced, in which more newly colonized patients were identified in the subsequent weeks. Attention to hand hygiene was enforced, and the hypothesis of contamination from “wet” environmental locations was tested by performing cultures of sinks and shower drains. In June and July, 47 of 241 environmental cultures (19.5%) were positive for E. cloacae with an identical antibiogram, among which some were typed as genotype A. To diminish the environmental contamination, all siphons of sinks were replaced, and disinfection of sinks and shower drains was intensified using chlorine and soda on a daily basis. Replacement of shower drains was not possible. After this intervention, the incidence of newly colonized patients declined gradually. A change in the regimen of selective gut decontamination in hematology patients was considered as an alternative intervention, but with the decrease in new patient cases, this was not implemented. A final round of environmental cultures at the end of August revealed 8 positive cultures, of which 5 were positive for genotype A. In retrospect, this finding could be explained by the fact that the cleaning team did not follow the intensified instructions for disinfection. From week 29, genotype A E. cloacae was no longer cultured in weekly patient screenings. Based on this observation, it is important that in (re)building plans for hospitals, a master plan for the prevention of nosocomial transmission from environment to patients is incorporated.Funding: NoneDisclosures: None

Carbapenemase-producing Enterobacterales in hospital drains in Southern Ontario, Canada

Hospital drains may be an important reservoir for carbapenemase-producing Enterobacterales (CPE). To determine prevalence of CPE in hospital drains exposed to inpatients with CPE, relatedness of drain and patient CPE, and risk factors for drain contamination. Sink and shower drains in patient rooms and communal shower rooms exposed to 310 inpatients with CPE colonization/infection were cultured at 10 hospitals. Using short- and long-read whole-genome sequencing, inpatient and corresponding drain CPE were compared. Risk factors for drain contamination were assessed using multi-level modelling. Of 1209 exposed patient room and communal shower room drains, 53 (4%) yielded 62 CPE isolates in seven (70%) hospitals. Of 49 CPE isolates in patient room drains, four (8%) were linked to prior room occupants. Linked drain/room occupant pairs included Citrobacter freundii ST18 isolates separated by eight single nucleotide variants (SNVs), related blaKPC-containing IncN3-type plasmids (different species), related blaKPC-3-containing IncN-type plasmids (different species), and related blaOXA-48-containing IncL/M-type plasmids (different species). In one hospital, drain isolates from eight rooms on two units were Enterobacter hormaechei separated by 0-6 SNVs. Shower drains were more likely to be CPE-contaminated than hand hygiene (odds ratio: 3.45; 95% confidence interval: 1.66-7.16) or patient-use (13.0; 4.29-39.1) sink drains. Hand hygiene sink drains were more likely to be CPE-contaminated than patient-use sink drains (3.75; 1.17-12.0). Drain contamination was uncommon but widely dispersed. Drain CPE unrelated to patient exposure suggests contamination by undetected colonized patients or retrograde (drain-to-drain) contamination. Drain types had different contamination risks.

Role of Sinks as an Environmental Reservoir in CPE Outbreak in a Burn Intensive Care Unit

<h3>Background</h3> The incidence of carbapenemase- producing enterobacteriacae (CPE) is steadily increasing in health care settings. Sink drains have been identified as a reservoir for transmission of CPE. We describe a CPE outbreak in a burn intensive care unit (ICU), where we identified CPE contaminated sink drains as the most likely source of transmission. <h3>Methods</h3> The surveillance and infection control measures undertaken to contain the outbreak included weekly microbiological screening, environmental sampling of sink drains, shower drains, ice machine, and hydrotherapy hoses. Plasmid analysis was performed on the patient isolates. <h3>Results</h3> There were 3 nosocomial Klebsiella pneumoniae carbapenemase-producing (KPC) cases identified between September and November 2019 including 2 bloodstream infections. The first case was not on the unit at the same time as the two subsequent cases. Plasmid analysis of the three cases revealed that they were identical. As part of outbreak control measures, admission to the unit was restricted, staff were cohorted to care for CPE positive and negative patients, and CPE positive patients were geographically separated to one side of the unit. Polymerase chain reaction (PCR) testing of sink drain swabs identified 3 KPC positive sinks. One of the sinks was epidemiologically linked to the cases. No other water sources tested positive. Retrospective case reviews and four-weekly point prevalence identified no additional cases. <h3>Conclusions</h3> The outbreak investigation shows that CPE positive sink drains were likely implicated in the transmission of this CPE outbreak especially given the absence of any patient source on the unit during the first transmission. This outbreak re-affirms the role that contaminated water sources play in CPE transmission and the importance of sink design and other engineering solutions to prevent dispersion of CPE from ICU sink drains.

1228. Risk Factors for Contamination with Carbapenemase-Producing Enterobacteriales (CPE) in Exposed Hospital Drains in Ontario, Canada

BackgroundHospital drains may be a source of CPE in patients. We determined prevalence of and risk factors for CPE contamination of hospital drains exposed to patients with CPE colonization/infection.MethodsWe cultured hand hygiene and patient use sink as well as tub/shower drains exposed to 310 inpatients colonized/infected with CPE in 10 Ontario hospitals. A multi-level logistic regression model was fitted to determine whether type of drain/room/unit was associated with CPE drain contamination. Drain and room occupant CPE isolates underwent Illumina whole-genome and MinION sequencing. Single nucleotide variant (SNV) phlogenomic analyses and plasmid characterization were performed.Results53/ Of the 1,209 drains, 53 (4%) at 7 (70%) hospitals yielded CPE. Patient room shower drains were significantly more likely to yield CPE than hand hygiene sink (OR 3.35, 95% CI 1.61–6.97) and patient use sink (OR 10.89, 95% CI 3.62–32.80) drains. Hand hygiene sink drains were significantly more likely to yield CPE than patient use sink drains (OR 3.26, 95% CI 1.05–10.13). 8 (15%) drain isolates matched the room occupant CPE gene/species; 24 (44%) matched the gene but not species, and 23 (42%) matched neither gene nor species. Among 13 drain/11 room occupant pairs with molecular comparisons to date, only 1/13 (8%) drain isolates matched the respective room occupant carbapenemase allele and replicon harboring the carbapenemase gene (IncN replicon harboring blaKPC-3). In addition, one drain isolate had a plasmid highly related to plasmids of 2 isolates from a patient occupying a room in an adjacent unit (IncN3 replicons harboring blaKPC-2). At another hospital, all 6 drain isolates were located on one unit and had an IncHI2A/HI2/TrfA replicon harboring blaNDM-1; 5 of these were E. cloacae ST66, with 0–3 SNV differences observed between isolates.ConclusionDifferent drain types have different risks of CPE contamination. In our setting, most drain contamination was not caused by recognized room occupants. Further investigation is needed to understand the sources of hospital drain CPE contamination.Disclosures All authors: No reported disclosures.

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

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.

Control of Multidrug Resistant Pseudomonas Aeruginosa through Hospital Construction Design and Extensive Environmental and Clinical Surveillance in an Allogeneic Transplantat Unit

▪Introduction: Immunocompromised patients are increasingly threatened by multidrug resistant bacterial strains. Following allogeneic stem cell transplantation (SCT), patients are especially at risk for multidrug resistant Pseudomonas aeruginosa (MRPA) which as a pathogen can be the cause of life-threatening septicemias. A possible reservoir and source of nosocomial infections are biofilms in shower drains, sinks, and toilets. For this reason, substantial targeted renovation was performed in the bathrooms of our SCT unit. We subsequently performed extensive surveillance of patients status as carriers and took numerous environmental samples.Methods: Renovation/ conversion works of our transplant unit (2 wards with 20 HEPA filtered patients rooms, all equipped with separate shower baths) began in 2011 and included the installation of Pall-Aquasafe water filters (Pall Cooperation, Port Washington, NY) on all faucet and shower heads. Washbasins were equipped with Biorec Disinfection siphons (MoveoMed, Radebeul, Germany), which use UV and temperature together with frequent vibration and a bactericidal coating for disinfection. In addition, the toilets were replaced with rimless toilet basins and a system was developed to supply the flushing water with disinfectant at appropriate concentrations. The shower outlet drains were modified and covered by a heavy metal lid that cannot be easily removed and prevents aerosol formation. All renovation work was completed in April 2014. Cleaning and disinfection takes place once a day and the removable metal devices of the showers are sterilized once a week as well as every time a patient is discharged. In addition, extensive training of all personal in infection prevention was performed and the work of the cleaning personal was supervised closely. Environmental sampling was performed monthly in every room. Patients were screened upon admission and weekly during their treatment on the SCT unit by either anal swabs or stool cultures. Standard antibiotic prophylaxis consisted of ciprofloxacin and metronidazole for patients undergoing allogeneic SCT. Metronidazole prophylaxis was omitted in August 2013.Results: Peri-renovation environmental sampling detected MRPA in 22,6% of swabs from the toilets and 11,8% of swabs from the shower outlets in 2012. The rate decreased to 15,1% from the toilets and 4,4% from the shower outlets in 2013 and reached 10,1% from the toilets and 0,6% from the shower outlets in the first six months of 2014. In 2012, 15 out of 197 patients (7.6%), receiving an allogeneic SCT or treatment for severe post-transplant complications (mainly GvHD) were affected by MRPA. This number decreased to 13 out of 206 (6.3%) in 2013 and 2 out of 95 (2.1%) in the first half in 2014. Overall 18 patients (3.6%) were colonized only and 12 patients (2.4%) developed bacteremia from MRPA.Discussion: Environmental sources must be taken into consideration for the prevention of nosocomial infections. The implemented measures in our transplant unit can serve as an example for the reduction of biofilm, which can act as a reservoir for MRPA. Because of inconsistent local conformity of environmental and clinical isolates it still remains unclear whether the reason for colonisation and infection lays in environmental contamination and / or antibiotic selection in already precolonized patients. Further investigations will employ MRPA genotyping to determine genetic relationships between isolates from patients and environmental isolates. DisclosuresNo relevant conflicts of interest to declare.

Efficient drain water heat recovery in horizontal domestic shower drains

Much of the energy utilised in domestic water heating is wasted to the drainage system by applications such showers, baths, dishwashers etc. The recovery of this waste heat from domestic waste water flows has been shown to be a viable method of improving the energy efficiency of buildings. However, many existing systems only operate satisfactorily when the heat exchanger is in a vertical orientation due to the nature of waste water flow within drain pipes. This orientation requirement presents a barrier to the full scale implementation of this technology as many dwellings may not have sufficient space to accommodate a vertical heat exchanger in their waste drainage system. This paper outlines the development and analysis of a horizontal drain water heat recovery system for domestic showers. The results of the investigation show that it is possible to recover energy from horizontal shower drains using a drain water heat recovery device at a satisfactory level of efficiency. The results also demonstrate that such a system may be economically viable depending on a number or external factors. The implementation of this technology on a national level was shown to have the potential to reduce energy usage and CO2 emissions significantly.

Plasmids and Bacterial Strains Mediating Multidrug-Resistant Hospital-Acquired Infections Are Coresidents of the Hospital Environment

Hospital-acquired infections (HAIs) are a global problem. The widespread use of antibiotics continues to exacerbate the problem giving rise to antibiotic-resistant bacteria both in and outside a clinical context. The general hospital environment is an obvious important focus for the selection and spread of multiresistant bacteria and a potential direct source of HAIs. Despite this, there are few detailed studies that have investigated the relationship between strains mediating HAIs and strains coresident in the hospital. Here we isolated bacteria from patients with HAIs exhibiting resistance to β-lactam antibiotics over a 1-month period in 2011. Three of these isolates were examined in detail by molecular analysis and their multiresistance regions were compared to β-lactam resistant bacteria isolated from the immediate hospital environment over the same period. All sampled patients were in a 14-bed burns unit and the environmental sample sites included shower drains, sinks, trolleys, and door handles. It was found that identical strains carrying the same resistance regions were present in both patients and the hospital environment suggesting HAIs can arise from bacteria resident in the immediate surrounds. The three patient infections were not derived from a single source, since strains could be distinguished by the genotype and spatial location. While it seems unlikely that eradication of multiresistant bacteria from the hospital can be achieved, more effective hospital cleaning and a better hospital design may be able to reduce transmission.

Pseudomonas aeruginosa Outbreak in a Pediatric Intensive Care Unit Linked to a Humanitarian Organization Residential Center

Pseudomonas aeruginosa commonly colonizes the hospital environment. Between April 2006 and September 2008, we investigated an outbreak of P. aeruginosa infection occurring in a pediatric intensive care unit. We conducted epidemiologic and molecular investigations to identify the source of the outbreak. Retrospective case finding; surveillance cultures of patients and environmental sites; admission screening; case-control study; and molecular typing. Infants and children in a pediatric intensive care unit of a tertiary-care institution. Thirty-seven cases of P. aeruginosa infection or colonization were detected between April 2006 and September 2008, including 3 fatal bloodstream infections. A closely-related strain was detected in 4 residents of a humanitarian nongovernmental organization (NGO) center who developed an infection, from 4 additional residents upon their hospital admission, and from a sink drain at the NGO residential center. NGO recipients represented 65% (24/37) of the total number of cases of P. aeruginosa colonization or infection during the outbreak period. Investigation at the residential center showed widespread contamination of the sewage system (10/14 sinks and shower drains, 70%) and a high prevalence (38%) of P. aeruginosa carriage among children. These findings suggest that the probable cause of the outbreak was the contamination of the NGO residential center with further nosocomial transmission after admission, and highlight the importance of considering external sources when investigating hospital outbreaks.

Shower water heat recovery in high-rise residential buildings of Hong Kong

This paper investigates the potential for shower water heat recovery from bathrooms equipped with instantaneous water heaters in high-rise residential buildings of Hong Kong. A simple single-pass counter-flow heat exchanger installed horizontally beneath the shower drain is employed as a localized heat recovery measure for preheating cold water going to a water heater. The thermal energy exchange is evaluated using the effectiveness-number of transfer units ( ε-NTU) approach. Shower usage patterns including shower operating time and water flow rate sampled from an interview survey via the Monte-Carlo sampling technique, together with the water temperatures at the shower heads, shower drains and cold water supply mains recorded in sample shower operations, are the input parameters. The results indicate that 4–15% shower water heat can be recovered through a 1.5 m long single-pass counter-flow heat exchanger for a drainage pipe of diameter 50 mm.