Methicillin-resistant Staphylococcus aureus (MRSA) is an opportunistic pathogen which commonly colonizes people before causing an infection. MRSA is a common and important cause of healthcare-associated infections. MRSA is transmitted through direct or indirect contact with health care workers (HCW) serving as the primary vector for transmission in the health care setting. In acute care settings, we use Contact Precautions (single room, gown and gloves for all patient-HCW contact, patient room restriction) for patients colonized with MRSA to prevent transmission to other patients. In long term care settings, current Centers for Disease Control and Prevention (CDC) Multidrug Resistant Organisms Guidelines suggest modifying Contact Precautions, but there is little evidence to guide how to modify them. The use of gowns, gloves and hand washing prevent MRSA transmission; however, their use detracts from a patient-centered, home-like environment which is an important priority for nursing homes. The PI and colleagues developed a surrogate measure of transmission, detection of MRSA on HCW gown and gloves during HCW-patient interactions. Thus, we can identify patient care activities that are most likely to lead to transmission and thus provide evidence for prioritizing when disposable gowns and gloves should be worn or hand washing emphasized.
The primary objective of this protocol was to estimate the frequency of transmission of MRSA and risk factors for transmission of MRSA to disposable gowns and gloves worn by HCWs interacting with MRSA colonized long term care (LTC) residents in a prospective multisite observational study.
To meet this objective, we conducted a multi-center, prospective observational study to estimate the frequency of and risk factors for MRSA transmission to gowns and gloves when worn by healthcare workers when providing care to VA Community Living Center (CLC) residents.
The study was conducted in seven VA CLCs in Maryland, Texas, Massachusetts, and Washington DC. We used MRSA surveillance results to identify residents with a history of MRSA by surveillance or clinical culture in the year prior to enrollment. Eligible residents had an expected length of stay of at least one week, were not identified by nursing staff as having behavioral problems and were enrolled with written informed consent from them or their legally authorized representative. As a control group, we also enrolled 51 residents without a history of MRSA in the year prior to enrollment.
All study activities occurred in the resident's CLC. Each enrolled resident was cultured for MRSA and other bacteria from the anterior nares, perianal skin, and wound (if present). Demographic information, pertinent medical history, and the presence and type of skin breakdown, medical devices, and uncontrolled body secretions were recorded from the medical record. Each enrolled resident was followed for 6-25 study visits over four weeks.
HCW were enrolled with verbal informed consent. During each study visit, we asked enrolled HCW to wear disposable gowns and gloves during each usual care activity (e.g., wound dressing) that occurs during the study visit. A research coordinator observed and recorded the type of care delivered with each activity. At the end of each activity, the research coordinator swabbed the HCW's gown and gloves prior to disposing of them. Each swab was tested for MRSA and other bacteria to determine if MRSA or other bacteria from the resident was transferred to the HCW's gown or gloves during that episode of care.
For our primary analysis, residents were determined to be MRSA colonized if the anterior nares, perianal skin, or wound swab grew MRSA. The risk association between MRSA colonization and resident characteristics was measured using the chi square or Fisher's exact test for categorical variables, Student t-test or Wilcoxon rank sum for continuous variables. The risk of MRSA transmission for a particular type of care was estimated using a proportion (e.g., number of glove specimens collected during a specific type of care that grew MRSA divided by number of glove specimens collected during a specific type of care).
Odds ratios (the odds of MRSA transmission given receiving a particular type of care divided by the odds of MRSA transmission given not receiving that care) were calculated using generalized estimating equations (GEE) with an exchangeable covariance structure. GEE accounts for multiple observations from the same resident. Odds ratios significantly greater than 1 were considered high risk types of care and those significantly less than 1 (p<0.05) were considered low risk types of care. Care interactions with no transmission were also considered low risk care.
Two hundred residents were enrolled; 94 were MRSA colonized. Glove contamination was higher than gown contamination (20% vs. 11% of 1544 interactions; p<0.01). Transmission varied greatly by type of care from 0% to 19% for gowns and 7% to 37% for gloves. We identified high risk activities (Odds ratios >1.0; p<0.05) including: changing dressings (e.g., wound, j-tube), dressing the resident, providing hygiene (brushing teeth, combing hair), and bathing the resident. We identified low risk activities (Odds ratios <1.0; p<0.05) as giving medications, testing blood glucose, and feeding.
The VA Gown and Glove study goal was to identify the types of care provided in VA CLCs that are most likely to allow MRSA and other bacteria to spread to other residents.
With this information, we can be more specific in when HCWs need to wear gowns and gloves and wash their hands when caring for MRSA colonized residents, creating a more resident-centered, home-like environment in the Community Living Centers.
Results of this study been shared with study sites and the VA Multidrug Resistant Organism (MDRO) Prevention Program. The results were incorporated into the VHA Guideline for Implementation of the VHA MRSA Prevention Initiative in CLCs, improving care for veterans in the CLCs.
- Pineles L, Morgan DJ, Lydecker A, Johnson JK, Sorkin JD, Langenberg P, Blanco N, Lesse A, Sellick J, Gupta K, Leykum L, Cadena J, Lepcha N, Roghmann MC. Transmission of methicillin-resistant Staphylococcus aureus to health care worker gowns and gloves during care of residents in Veterans Affairs nursing homes. American journal of infection control. 2017 Sep 1; 45(9):947-953.