Bacterial contamination on used face masks among nursing home healthcare personnel.

Objectives: Since the beginning of the COVID-19 pandemic, face masks have been worn by many in public areas and for prolonged periods by healthcare workers (HCWs). This may facilitate bacterial contamination and transmission to and from patients in nursing homes where clinical care areas with strict precautions and residential and activity areas are interconnected. We assessed and compared bacterial mask colonization in HCWs belonging to different demographic categories and professions (clinical and nonclinical) and among HCWs who had worn the mask for different periods of time. Design setting and participants: We conducted a point-prevalence study of 69 HCW masks at the end of a typical work shift in a 105-bed nursing home serving postacute care and rehabilitation patients. Information collected about the mask user included profession, age, sex, length of time the mask was worn, and known exposure to patients with colonization. Results: In total, 123 distinct bacterial isolates were recovered (1-5 isolates per mask), including Staphylococcus aureus from 11 masks (15.9%) and gram-negative bacteria of clinical importance from 22 masks (31.9%). Antibiotic resistance rates were low. There were no significant differences in the number of clinically important bacteria among masks worn more or less than 6 hours, and there were no significant differences among HCWs with different job functions or exposure to colonized patients. Conclusions: Bacterial mask contamination was not associated with HCW profession or exposure and did not increase after 6 hours of mask wearing in our nursing home setting. Bacteria contaminating HCW masks may differ from those colonizing patients.

Bacterial contamination on used face masks in healthcare personnel

Background: Face masks have been worn universally and for long periods of time by healthcare personnel during the COVID-19 pandemic. They are frequently touched or adjusted with the hands and may come in contact with various surfaces and high-touch sites when taken off and on even briefly. These activities present opportunities for face masks to become contaminated with microorganisms. Nursing homes have high rates of multidrug-resistant bacteria and low PPE compliance;therefore, contamination of face masks in this setting may be of great interest. We investigated bacterial colonization status on used face masks in healthcare personnel, including assessing the presence of clinically important and multidrug-resistant bacteria. Methods: At a nursing home serving mostly post–acute-care patients, we collected 69 face masks from personnel at the end of the user's work shift. Information about the mask and the user was also collected via a self-reported survey. Face masks were incubated in BHI broth overnight at 36°C and 10 μL was then plated on selective and differential plates. Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and gram-negative bacteria (GNB) resistant to several antibiotic classes were identified using standard microbiological methods. Resistance testing for cefoxitin (S. aureus), ciprofloxacin, meropenem, tetracycline, erythromycin, gentamicin, trimethoprim–sulfamethoxazole, and ceftazidime with and without clavulanic acid (gram-negative bacteria) was performed using the disc diffusion technique on Mueller-Hinton plates (Kirby Bauer). Results: The job categories of face mask users were competency-evaluated nursing assistant or nursing assistant (22.73%), nurse (12.12%), and other or administrative (37.88%). Overall face mask contamination rates for MRSA (0%) and VRE (3.3%) were low;however, methicillin-susceptible S. aureus was found on 11 masks (15.9%). High contamination and resistance rates were found for gram-negative bacteria, with 113 isolates. Among them, 69 (60.9%) were resistant to at least 1 antibiotic, most commonly was erythromycin (59.4%). Additionally, higher rates of clinically important pathogenic gram-negative bacteria were identified: 14.3% of masks were contaminated with Klebsiella pneumoniae, 13.0% were contaminated with Enterobacter spp, and 4.2% were contaminated with Escherichia coli. Importantly, there were no significant differences in the total number of isolates of potential clinical significance recovered from masks worn >6 hours versus those worn <6 hours. Conclusions: Among nursing-home healthcare workers, face masks were often contaminated with multiple organisms, including potentially pathogenic bacteria and antibiotic-resistant gram-negative organisms. This contamination may pose a risk for transmission if face masks are not properly used and/or disposed of after wearing. Prolonged duration of face-mask wearing, however, was not associated with increased contamination rates.Funding: NoneDisclosures: None

Environmental Contamination with SARS-CoV-2 in Nursing Homes

Background The COVID-19 pandemic has disproportionately affected nursing home (NH) patients, accounting for 5% of all cases and 32% of all COVID-19 deaths nationwide. Little is known about the frequency and persistence of SARS-CoV-2 environmental contamination in NHs. We characterize SARS-CoV-2 contamination in the rooms of COVID-19 patients and common areas in and around COVID-19 units. Methods A prospective cohort study was conducted at four NHs in Michigan between October 2020 and January 2021. Clinical research personnel obtained swab specimens from high-touch room surfaces of COVID-19 infected patients, up to three times per patient. Weekly swab specimens from six high-touch surfaces in common areas were also obtained. Demographic and clinical data were collected from patient clinical records. Our primary outcome of interest was the probability of SARS-CoV-2 detection from specific environmental surfaces in COVID-19 patient rooms. Results One hundred four patients with COVID-19 were enrolled and followed for 241 visits. Patient characteristics included: 61.5% over the age of 80;67.3% female;89.4% non-Hispanic white;50.1% short-stay. The study population had significant disabilities in activities of daily living (ADL;81.7% dependent in four or more ADLs) and comorbidities including dementia (55.8%), diabetes (40.4%) and heart failure (32.7) (Table 1). Over the 3-month study period, 2087 swab specimens were collected (1896 COVID-19 patient room surfaces, 191 common area swabs). Figure 1 shows contamination rates at sites proximate and distant to the patient bed. SARS-CoV-2 positivity was 28.4% (538/1896 swabs) on patient room surfaces and 3.7% (7/191 swabs) on common area surfaces. Over the course of follow-up, 89.4% (93/104) of patients had SARS-CoV-2 contamination in their room at least once (Figure 2). Environmental contamination detected on enrollment correlated with contamination of the same site during follow-up. Functional independence increased the odds of proximate contamination. Table 1. Clinical and Demographic Characteristics of the Study Population Including Short- and Long-stay Patients Figure 1. Contamination of Environmental Surfaces Relative to Distance from Patient Bed Figure 2. SARS-CoV-2 on Swab Specimens Collected – Patient-level, Visit-level, and Swab-level Conclusion We conclude that environmental contamination of surfaces in the rooms of COVID-19 patients is nearly universal and persistent. Patients with greater independence are more likely than fully dependent patients to contaminate their immediate environment. Disclosures All Authors: No reported disclosures

Environmental contamination with SARS-CoV-2 in nursing homes.

BACKGROUND: SARS-CoV-2 outbreaks in nursing homes (NHs) have been devastating and have led to the creation of coronavirus disease 2019 (COVID-19) units within NHs to care for affected patients. Frequency and persistence of SARS-CoV-2 environmental contamination in these units have not been studied. METHODS: A prospective cohort study was conducted between October 2020 and January 2021 in four Michigan NHs. Swabs from high-touch surfaces in COVID-19-infected patient rooms were obtained at enrollment and follow-up. Demographic and clinical data were collected from clinical records. Primary outcome of interest was the probability of SARS-CoV-2 RNA detection from specific environmental surfaces in COVID-19 patient rooms. We used multivariable logistic regression to assess patient risk factors for SARS-CoV-2 contamination. Pairwise Phi coefficients were calculated to measure correlation of site-specific environmental detection upon enrollment and during follow-up. RESULTS: One hundred and four patients with COVID-19 were enrolled (61.5% >80 years; 67.3% female; 89.4% non-Hispanic White; 51% short stay) and followed up for 241 visits. The study population had significant disabilities in activities of daily living (ADL; 81.7% dependent in four or more ADLs) and comorbidities, including dementia (55.8%), diabetes (40.4%), and heart failure (32.7%). Over the 3-month study period, 2087 swab specimens were collected (1896 COVID-19 patient rooms, 191 common areas). SARS-CoV-2 positivity was 28.4% (538/1896 swabs) on patient room surfaces and 3.7% (7/191 swabs) on common area surfaces. Nearly 90% (93/104) of patients had SARS-CoV-2 contamination in their room at least once. Environmental contamination upon enrollment correlated with contamination of the same site during follow-up. Functional independence increased the odds of proximate contamination. CONCLUSIONS: Environmental detection of viral RNA from surfaces in the rooms of COVID-19 patients is nearly universal and persistent; more investigation is needed to determine the implications of this for infectiousness. Patients with greater independence are more likely than fully dependent patients to contaminate their immediate environment.