Timing and route of contamination of hospitalized patient rooms with healthcare-associated pathogens

Update on potential interventions to reduce the risk for transmission of health care-associated pathogens from floors and sinks

Health care facility floors and sink drains and other wastewater drainage sites are universally contaminated with potential pathogens and there are plausible mechanisms by which organisms can be disseminated from these sites. However, floors and sink drains are not addressed as potential sources of pathogen transmission in most health care facilities. One factor that has hindered progress in addressing floors and sinks has been the lack of practical and effective measures to reduce the risk for dissemination of organisms from these sites. This article provides an update on some of the potential interventions being used to reduce the risk for transmission of health care-associated pathogens from floors and sinks. Practical approaches to address these sites of contamination are emphasized.

Effectiveness of ultraviolet-C light treatment of shoes in reducing the transfer of pathogens into patient rooms by shoes of healthcare personnel

Contaminated shoes are a potential vector for dissemination of healthcare-associated pathogens. We demonstrated that healthcare personnel walking into patient rooms frequently transferred pathogens from their shoes to the floor. An 8-second treatment of shoes with a UV-C decontamination device significantly reduced the frequency of transfer of vegetative bacterial pathogens.

Dissemination of methicillin-resistant Staphylococcus aureus and bacteriophage MS2 from floors in long-term care facility resident rooms

We demonstrated that methicillin-resistant Staphylococcus aureus (MRSA) contamination on floors in the rooms of colonized long-term care facility residents was frequently transferred by shoes to adjacent patient rooms. A benign virus inoculated onto the floor was transferred to floors and high-touch surfaces in adjacent rooms and the nursing station. These results suggest that shoes may serve as a vector for dissemination of healthcare-associated pathogens from rooms of MRSA-colonized patients.

A randomized trial to determine whether wearing slippers reduces transfer of bacteriophage MS2 from floors to patients and surfaces in hospital rooms

In a randomized trial, patients wearing slippers whenever out of bed transferred bacteriophage MS2 from hospital room floors to patients and surfaces significantly less often than controls not provided with slippers. Wearing slippers could provide a simple means to reduce the risk for acquisition of healthcare-associated pathogens from contaminated floors.

Registration: ClinicalTrials.gov; NCT04935892

A randomized trial of ultraviolet-C (UV-C) light versus sodium hypochlorite delivered by an electrostatic sprayer for adjunctive decontamination of hospital rooms

In a randomized trial, adjunctive ultraviolet-C light treatment with a room decontamination device and sodium hypochlorite delivered via an electrostatic sprayer were similarly effective in significantly reducing residual healthcare-associated pathogen contamination on floors and high-touch surfaces after manual cleaning and disinfection. Less time until the room was ready to be occupied by another patient was required for electrostatic spraying.

Isolation of Clostridioides difficile PCR Ribotype 027 from single-use hospital gown ties

Background. Clostridioides difficile is a spore-forming pathogen responsible for antibiotic-associated diarrhoea. In the USA high incidence of C. difficile infection (CDI) in clinical environments has led to interest in C. difficile spore transmission.Hypothesis. Single use hospital surgical gown ties act as a reservoir for C. difficile spores.Aim. This study sought to examine whether single-use hospital surgical gown ties used in surgery, from an acute healthcare facility, harboured C. difficile spores.Methodology. Used surgical gowns ties worn by clinicians in the healthcare facility were examined for C. difficile spore presence via spread plate and anaerobic culture. The colonies isolated from each gown tie were subcultured on C. difficile selective agar for phenotypic confirmation. Presumptive C. difficile colonies were examined using C. difficile Quik Check Complete, 16-23S PCR Ribotyping and MALDI-TOF analysis.Results. In total 17 suspected C. difficile colonies were isolated from 15 gown ties via culture. C. difficile Quik Check Complete found two isolates as possible C. difficile. MALDI-TOF and PCR Ribotyping confirmed one isolate as C. difficile PCR ribotype 027 associated with clinical outbreaks.Discussion. Our study revealed the presence of hypervirulent C. difficile ribotype 027 spores on single-use gown ties. This highlights the potential of gown ties as a vector of spore transmission across clinical environments, especially when gowns are not worn appropriately.Conclusions. Appropriate compliance to infection control procedures by healthcare workers is essential to prevent spore dissemination across clinical facilities and reduce CDI rates.

Matching Clostridioides difficile strains obtained from shoe soles of healthcare workers epidemiologically linked to patients and confirmed by whole genome sequencing

BACKGROUND

The source of transmission of Clostridioides difficile in healthcare institutions is frequently unknown. The aim of this prospective cohort study was to assess the association between strains cultured from patients and shoe soles of healthcare workers (HCW), as already shown in the operation theatre, but not on general hospital wards in an acute care institution.

METHODS

We conducted a study at a university tertiary care center in Switzerland. From October 2019 to July 2020, shoe soles of HCW were cultured for C. difficile twice per shift while taking care of a patient infected with toxigenic C. difficile. Additional risk factors were assessed by interviewing involved HCW. Patients' fecal samples were processed by routine microbiological methods. Similarity of the HCWs' and patients' strains was determined by whole genome sequencing (WGS).

RESULTS

103 HCW exposed to 42 hospitalized patients participated in the study, providing 206 samples. Contamination of shoe soles with C. difficile was detected in 37 samples (17.8%) of HCW taking care of patients infected with C. difficile. Overall, transmission was suspected by epidemiological link and matching strains demonstrated by WGS in 74%.

CONCLUSIONS

HCW' shoe soles were positive in 17.8% with C. difficile strains linked epidemiologically and confirmed by WGS to infected patients suggesting potential transmission by HCWs' shoe soles. This pilot study provides sufficient evidence to further evaluate this potential mode of healthcare-associated transmission of C. difficile by a larger clinical trial.

Is the Antibacterial Activity of Multi-Walled Carbon Nanotubes (MWCNTs) Related to Antibiotic Resistance? An Assessment in Clinical Isolates

Antimicrobial resistance has spread globally, compromising the treatment of common infections. This feature is particularly harmful for nosocomial pathogens that can survive on hospital surfaces. Research studies have been conducted to evaluate new materials that are able to counteract the microbial growth and the colonization of the hospital environment. In this context, nanotechnologies have showed encouraging applications. We investigated the antibacterial activity of multi-walled carbon nanotubes (MWCNTs), both pristine (p) and functionalized (f), at concentrations of 50 and 100 μg mL⁻¹, against bacterial strains isolated from hospital-acquired infections, and this activity was correlated with the antibiotic susceptibility of the strains. The inhibiting effect of MWCNTs occurred for both types and doses tested. Moreover, f-MWCNTs exerted a greater inhibiting effect, with growth decreases greater than 10% at 24 h and 20% at 48 h compared to p-MWCNTs. Moreover, a lower inhibitory effect of MWCNTs, which was more lasting in Gram-positives resistant to cell wall antibiotics, or temporary in Gram-negatives resistant to nucleic acid and protein synthesis inhibitors, was observed, highlighting the strong relation between antibiotic resistance and MWCNT effect. In conclusion, an antimicrobial activity was observed especially for f-MWCNTs that could therefore be loaded with bioactive antimicrobial molecules. However, this potential application of CNTs presupposes the absence of toxicity and therefore total safety for patients.

Microbial bioburden of inpatient and outpatient areas beyond patient hospital rooms

OBJECTIVE

To investigate the frequency of environmental contamination in hospital areas outside patient rooms and in outpatient healthcare facilities.

DESIGN

Culture survey.

SETTING

This study was conducted across 4 hospitals, 4 outpatient clinics, and 1 surgery center.

METHODS

We conducted 3 point-prevalence culture surveys for methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridioides difficile, Candida spp, and gram-negative bacilli including Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter baumanii, and Stenotrophomonas maltophilia in each facility. In hospitals, high-touch surfaces were sampled from radiology, physical therapy, and mobile equipment and in emergency departments, waiting rooms, clinics, and endoscopy facilities. In outpatient facilities, surfaces were sampled in exam rooms including patient and provider areas, patient bathrooms, and waiting rooms and from portable equipment. Fluorescent markers were placed on high-touch surfaces and removal was assessed 1 day later.

RESULTS

In the hospitals, 110 (9.4%) of 1,195 sites were positive for 1 or more bacterial pathogens (range, 5.3%-13.7% for the 4 hospitals) and 70 (5.9%) were positive for Candida spp (range, 3.7%-5.9%). In outpatient facilities, 31 of 485 (6.4%) sites were positive for 1 or more bacterial pathogens (range, 2% to 14.4% for the 5 outpatient facilities) and 50 (10.3%) were positive for Candida spp (range, 3.9%-23.3%). Fluorescent markers had been removed from 33% of sites in hospitals (range, 28.4%-39.7%) and 46.3% of sites in outpatient clinics (range, 7.4%-82.8%).

CONCLUSIONS

Surfaces in hospitals outside patient rooms and in outpatient facilities are frequently contaminated with healthcare-associated pathogens. Improvements in cleaning and disinfection practices are needed to reduce contamination.