Candida auris is an emerging fungal pathogen increasingly recognized as a cause of healthcare-associated infections including outbreaks.

We performed a mixed-methods study to characterize the emergence of C. auris in the state of Maryland from 2019 to 2022, with a focus on socioeconomic vulnerability and infection prevention opportunities. We describe all case-patients of C. auris among Maryland residents from June 2019 to December 2021 detected by Maryland Department of Health. We compared neighborhood socioeconomic characteristics of skilled nursing facilities (SNFs) with and without C. auris transmission outbreaks using both the social vulnerability index (SVI) and the area deprivation index (ADI). The SVI and the ADI were obtained at the state level, with an SVI ≥ 75th percentile or an ADI ≥ 80th percentile considered severely disadvantaged. We summarized infection control assessments at SNFs with outbreaks using a qualitative analysis.

A total of 140 individuals tested positive for C. auris in the study period in Maryland; 46 (33%) had a positive clinical culture. Sixty (43%) were associated with a SNF, 37 (26%) were ventilated, and 87 (62%) had a documented wound. Separate facility-level neighborhood analysis showed SNFs with likely C. auris transmission were disproportionately located in neighborhoods in the top quartile of deprivation by the SVI, characterized by low socioeconomic status and high proportion of racial/ethnic minorities. Multiple infection control deficiencies were noted at these SNFs.

Neighborhood socioeconomic vulnerability may contribute to the emergence and transmission of C. auris in a community.

To test the feasibility of targeted gown and glove use by healthcare personnel caring for high-risk nursing-home residents to prevent Staphylococcus aureus acquisition in short-stay residents.

Uncontrolled clinical trial.

This study was conducted in 2 community-based nursing homes in Maryland.

The study included 322 residents on mixed short- and long-stay units.

During a 2-month baseline period, all residents had nose and inguinal fold swabs taken to estimate S. aureus acquisition. The intervention was iteratively developed using a participatory human factors engineering approach. During a 2-month intervention period, healthcare personnel wore gowns and gloves for high-risk care activities while caring for residents with wounds or medical devices, and S. aureus acquisition was measured again. Whole-genome sequencing was used to assess whether the acquisition represented resident-to-resident transmission.

Among short-stay residents, the methicillin-resistant S. aureus acquisition rate decreased from 11.9% during the baseline period to 3.6% during the intervention period (odds ratio [OR], 0.28; 95% CI, 0.08–0.92; P = .026). The methicillin-susceptible S. aureus acquisition rate went from 9.1% during the baseline period to 4.0% during the intervention period (OR, 0.41; 95% CI, 0.12–1.42; P = .15). The S. aureus resident-to-resident transmission rate decreased from 5.9% during the baseline period to 0.8% during the intervention period.

Targeted gown and glove use by healthcare personnel for high-risk care activities while caring for residents with wounds or medical devices, regardless of their S. aureus colonization status, is feasible and potentially decreases S. aureus acquisition and transmission in short-stay community-based nursing-home residents.

To evaluate the effect of the burden of Staphylococcus aureus colonization of nursing home residents on the risk of S. aureus transmission to healthcare worker (HCW) gowns and gloves.

Multicenter prospective cohort study.

Residents and HCWs from 13 community-based nursing homes in Maryland and Michigan.

Residents were cultured for S. aureus at the anterior nares and perianal skin. The S. aureus burden was estimated by quantitative polymerase chain reaction detecting the nuc gene. HCWs wore gowns and gloves during usual care activities; gowns and gloves were swabbed and then cultured for the presence of S. aureus.

In total, 403 residents were enrolled; 169 were colonized with methicillin-resistant S. aureus (MRSA) or methicillin-sensitive S. aureus (MSSA) and comprised the study population; 232 were not colonized and thus were excluded from this analysis; and 2 were withdrawn prior to being swabbed. After multivariable analysis, perianal colonization with S. aureus conferred the greatest odds for transmission to HCW gowns and gloves, and the odds increased with increasing burden of colonization: adjusted odds ratio (aOR), 2.1 (95% CI, 1.3–3.5) for low-level colonization and aOR 5.2 (95% CI, 3.1–8.7) for high level colonization.

Among nursing home patients colonized with S. aureus, the risk of transmission to HCW gowns and gloves was greater from those colonized with greater quantities of S. aureus on the perianal skin. Our findings inform future infection control practices for both MRSA and MSSA in nursing homes.

To estimate the risk of transmission of antibiotic-resistant Gram-negative bacteria (RGNB) to gowns and gloves worn by healthcare personnel (HCP) when providing care to residents of community-based nursing facilities to identify the types of care and resident characteristics associated with transmission.

Prospective observational study.

Residents and HCP from 13 community-based nursing facilities in Maryland and Michigan.

Perianal swabs were collected from residents and cultured to detect RGNB. HCP wore gowns and gloves during usual care activities, and at the end of each interaction, these were swabbed in a standardized manner. Transmission of RGNB from a colonized resident to gowns and gloves was estimated. Odds ratios (ORs) of transmission associated with type of care or resident characteristic were calculated.

We enrolled 403 residents and their HCP in this study. Overall, 19% of enrolled residents with a perianal swab (n=399) were colonized with at least 1 RGNB. RGNB transmission to either gloves or gowns occurred during 11% of the 584 interactions. Showering the resident, hygiene or toilet assistance, and wound dressing changes were associated with a high risk of transmission. Glucose monitoring and assistance with feeding or medication were associated with a low risk of transmission. Residents with a pressure ulcer were 3 times more likely to transmit RGNB than residents without one (OR, 3.3; 95% confidence interval [CI], 1.0–11.1).

Gown and glove use in community nursing facilities should be prioritized for certain residents and care interactions that are deemed a high risk for transmission.

To directly observe healthcare workers in a nursing home setting to measure frequency and duration of resident contact and infection prevention behavior as a factor of isolation practice

Observational study

Healthcare workers in 8 VA nursing homes in Florida, Maryland, Massachusetts, Michigan, Washington, and Texas

Over a 15-month period, trained research staff without clinical responsibilities on the units observed nursing home resident room activity for 15–30-minute intervals. Observers recorded time of entry and exit, isolation status, visitor type (staff, visitor, etc), hand hygiene, use of gloves and gowns, and activities performed in the room when visible.

A total of 999 hours of observation were conducted across 8 VA nursing homes during which 4,325 visits were observed. Residents in isolation received an average of 4.73 visits per hour of observation compared with 4.21 for nonisolation residents (P<.01), a 12.4% increase in visits for residents in isolation. Residents in isolation received an average of 3.53 resident care activities per hour of observation, compared with 2.46 for residents not in isolation (P<.01). For residents in isolation, compliance was 34% for gowns and 58% for gloves. Healthcare worker hand hygiene compliance was 45% versus 44% (P=.79) on entry and 66% versus 55% (P<.01) on exit for isolation and nonisolation rooms, respectively.

Healthcare workers visited residents in isolation more frequently, likely because they required greater assistance. Compliance with gowns and gloves for isolation was limited in the nursing home setting. Adherence to hand hygiene also was less than optimal, regardless of isolation status of residents.

Infect Control Hosp Epidemiol 2018;39:683–687

To estimate the costs of 3 MRSA transmission prevention scenarios compared with standard precautions in community-based nursing homes.

Cost analysis of data collected from a prospective, observational study.

Care activity data from 401 residents from 13 nursing homes in 2 states.

Cost components included the quantities of gowns and gloves, time to don and doff gown and gloves, and unit costs. Unit costs were combined with information regarding the type and frequency of care provided over a 28-day observation period. For each scenario, the estimated costs associated with each type of care were summed across all residents to calculate an average cost and standard deviation for the full sample and for subgroups.

The average cost for standard precautions was $100 (standard deviation [SD], $77) per resident over a 28-day period. If gown and glove use for high-risk care was restricted to those with MRSA colonization or chronic skin breakdown, average costs increased to $137 (SD, $120) and $125 (SD, $109), respectively. If gowns and gloves were used for high-risk care for all residents in addition to standard precautions, the average cost per resident increased substantially to $223 (SD, $127).

The use of gowns and gloves for high-risk activities with all residents increased the estimated cost by 123% compared with standard precautions. This increase was ameliorated if specific subsets (eg, those with MRSA colonization or chronic skin breakdown) were targeted for gown and glove use for high-risk activities.

Infect Control Hosp Epidemiol 2016;37:962–966

To define how often methicillin-resistant Staphylococcus aureus (MRSA) is spread from resident to resident in long-term care facilities using whole-genome sequencing

Prospective cohort study

A long-term care facility

Elderly residents in a long-term care facility

Cultures for MRSA were obtained weekly from multiple body sites from residents with known MRSA colonization over 12-week study periods. Simultaneously, cultures to detect MRSA acquisition were obtained weekly from 2 body sites in residents without known MRSA colonization. During the first 12-week cycle on a single unit, we sequenced 8 MRSA isolates per swab for 2 body sites from each of 6 residents. During the second 12-week cycle, we sequenced 30 MRSA isolates from 13 residents with known MRSA colonization and 3 residents who had acquired MRSA colonization.

MRSA isolates from the same swab showed little genetic variation between isolates with the exception of isolates from wounds. The genetic variation of isolates between body sites on an individual was greater than that within a single body site with the exception of 1 sample, which had 2 unrelated strains among the 8 isolates. In the second cycle, 10 of 16 residents colonized with MRSA (63%) shared 1 of 3 closely related strains. Of the 3 residents with newly acquired MRSA, 2 residents harbored isolates that were members of these clusters.

Point prevalence surveys with whole-genome sequencing of MRSA isolates may detect resident-to-resident transmission more accurately than routine surveillance cultures for MRSA in long-term care facilities.

Infect Control Hosp Epidemiol 2016;37:685–691

To estimate the frequency of methicillin-resistant Staphylococcus aureus (MRSA) transmission to gowns and gloves worn by healthcare workers (HCWs) interacting with nursing home residents to better inform infection prevention policies in this setting

Observational study

Participants were recruited from 13 community-based nursing homes in Maryland and Michigan

Residents and HCWs from these nursing homes

Residents were cultured for MRSA at the anterior nares and perianal or perineal skin. HCWs wore gowns and gloves during usual care activities. At the end of each activity, a research coordinator swabbed the HCW’s gown and gloves.

A total of 403 residents were enrolled; 113 were MRSA colonized. Glove contamination was higher than gown contamination (24% vs 14% of 954 interactions; P<.01). Transmission varied greatly by type of care from 0% to 24% for gowns and from 8% to 37% for gloves. We identified high-risk care activities: dressing, transferring, providing hygiene, changing linens, and toileting the resident (OR >1.0; P<.05). We also identified low-risk care activities: giving medications and performing glucose monitoring (OR<1.0; P<.05). Residents with chronic skin breakdown had significantly higher rates of gown and glove contamination.

MRSA transmission from MRSA-positive residents to HCW gown and gloves is substantial; high-contact activities of daily living confer the highest risk. These activities do not involve overt contact with body fluids, skin breakdown, or mucous membranes, which suggests the need to modify current standards of care involving the use of gowns and gloves in the nursing home setting.

Infect. Control Hosp. Epidemiol. 2015;36(9):1050–1057

To determine whether enhanced daily cleaning would reduce contamination of healthcare worker (HCW) gowns and gloves with methicillin-resistant Staphylococcus aureus (MRSA) or multidrug-resistant Acinetobacter baumannii (MDRAB).

A cluster-randomized controlled trial.

Four intensive care units (ICUs) in an urban tertiary care hospital.

ICU rooms occupied by patients colonized with MRSA or MDRAB.

Extra enhanced daily cleaning of ICU room surfaces frequently touched by HCWs.

A total of 4,444 cultures were collected from 132 rooms over 10 months. Using fluorescent dot markers at 2,199 surfaces, we found that 26% of surfaces in control rooms were cleaned and that 100% of surfaces in experimental rooms were cleaned (P < .001). The mean proportion of contaminated HCW gowns and gloves following routine care provision and before leaving the rooms of patients with MDRAB was 16% among control rooms and 12% among experimental rooms (relative risk, 0.77 [95% confidence interval, 0.28-2.11]; P = .23). For MRSA, the mean proportions were 22% and 19%, respectively (relative risk, 0.89 [95% confidence interval, 0.50-1.53]; P = .16).

Intense enhanced daily cleaning of ICU rooms occupied by patients colonized with MRSA or MDRAB was associated with a nonsignificant reduction in contamination of HCW gowns and gloves after routine patient care activities. Further research is needed to determine whether intense environmental cleaning will lead to significant reductions and fewer infections.

ClinicalTrials.gov identifier: NCT01481935.

Colonization pressure is an important infection control metric. The aim of this study was to describe the definition and measurement of and adjustment for colonization pressure in nosocomial-acquisition risk factor studies of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Clostridium difficile.

We performed a computerized search of studies of nosocomial MRSA, VRE, and C. difficile acquisition published before July 1, 2009, through MEDLINE. Studies were included if a study outcome was MRSA, VRE, or C. difficile acquisition; the authors identified risk factors associated with MRSA, VRE, or C. difficile acquisition; and the study measured colonization pressure.

The initial MEDLINE search yielded 505 articles. Sixty-six of these were identified as studies of nosocomial MRSA, VRE, or C. difficile acquisition; of these, 18 (27%) measured colonization pressure and were included in the final review. The definition of colonization pressure varied considerably between studies: the proportion of MRSA- or VRE-positive patients (5 studies), the proportion of MRSA- or VRE-positive patient-days (6 studies), or the total or mean number of MRSA-, VRE-, or C. difficile-positive patients or patient-days (7 studies) in the unit over periods of varying length. In 10 of 13 studies, colonization pressure was independently associated with MRSA, VRE, or C. difficile acquisition.

There is a need for a simple and consistent method to quantify colonization pressure in both research and routine clinical care to accurately assess the effect of colonization pressure on cross-transmission of antibiotic-resistant bacteria.

To assess risk factors for methicillin-resistant Staphylococcus aureus (MRSA) acquisition among extended care residents focusing on level of care (residential vs rehabilitation) and room placement with an MRSA-positive resident.

Prospective cohort study.

Extended care units at 2 healthcare systems in Maryland.

Four hundred forty-three residents with no history of MRSA and negative MRSA surveillance cultures of the anterior nares and areas of skin breakdown at enrollment.

Follow-up cultures were collected every 4 weeks and/or at discharge for a period of 12 weeks. Study data were collected by a research nurse from the medical staff and the electronic medical records. Cox proportional hazards modeling was used to calculate adjusted hazards ratios (aHRs) and 95% confidence intervals (CIs).

Residents in rehabilitation care had 4-fold higher risk of MRSA acquisition compared with residents in residential care (hazard ratio [HR], 4. [95% CI, 2.2-8.8]). Being bedbound was significantly associated with MRSA acquisition in both populations (residential care, aHR, 4.3 [95% CI, 1.5-12.2]; rehabilitation care, aHR, 4.8 [95% CI, 1.2-18.7]). Having an MRSA-positive roommate was not significantly associated with acquisition in either population (residential care, aHR, 1.4 [95% CI, 0.5-3.9]; rehabilitation care, aHR, 0.5 [95% CI, 0.1-2.2]); based on concordant spa typing, only 2 of 8 residents who acquired MRSA and had room placement with an MRSA-positive resident acquired their MRSA isolate from their roommate.

Residents in rehabilitation care appear at higher risk and have different risk factors for MRSA acquisition compared to those in residential care.