Background-We comprehensively defined household longitudinal, strain-level Staphylococcus aureus transmission dynamics in households of children with community-associated methicillinresistant S. aureus (CA-MRSA) skin and soft tissue infection (SSTI).Methods-Between 2012-2015, 150 children, their household contacts, and pets were enrolled in a prospective cohort study in metropolitan Saint Louis, MO. Serial cultures to detect S. aureus were collected from three anatomic sites of household members, two dog/cat sites, and 21

IMPORTANCE Household environmental surfaces may serve as vectors for acquisition and spread of methicillin-resistant Staphylococcus aureus (MRSA) among household members, though few studies have evaluated which objects are important MRSA reservoirs. OBJECTIVES Determine the prevalence of environmental MRSA contamination in households of children with MRSA infection; define the molecular epidemiology of environmental, pet, and human MRSA strains within households; and identify factors associated with household MRSA contamination. DESIGN, SETTING, AND PARTICIPANTS Fifty households of children with active or recent culture-positive community-associated MRSA infection were enrolled from 2012–13 at St. Louis Children’s Hospital and community pediatric practices affiliated with the Washington University Pediatric and Adolescent Ambulatory Research Consortium. MAIN OUTCOMES AND MEASURES Participants’ nares, axillae, and inguinal folds were cultured to detect S. aureus colonization. Twenty-one environmental surfaces and pet dogs and cats were cultured. Molecular typing of S. aureus strains was performed by repetitive-sequence polymerase chain reaction to determine strain relatedness within households. RESULTS MRSA was recovered from environmental surfaces in 23 (46%) households, most frequently from the participant’s bed linens (18%), television remote control (16%), and bathroom hand towel (15%). MRSA colonized 12% of dogs and 7% of cats. At least 1 surface was contaminated with a strain type matching the participant’s isolate in 20 (40%) households. Participants colonized with S. aureus had a higher proportion of MRSA-contaminated surfaces (0.15 ± 0.17) than non-colonized participants [0.03± 0.06; mean difference 0.12 (95% CI 0.05, 0.20)]. A greater number of individuals per 1000 ft2 was also associated with a higher proportion of MRSA-contaminated surfaces (β=0.34, p=0.03). The frequency of cleaning household surfaces was not associated with S. aureus environmental contamination. CONCLUSIONS AND RELEVANCE MRSA strains concordant with infecting and colonizing strains are present on commonly handled household surfaces, a factor that likely perpetuates MRSA transmission and recurrent disease. Future studies are needed to determine methods to eradicate environmental contamination and prevent MRSA transmission in households.

Objective-We sought to determine the prevalence, molecular epidemiology, and factors associated with Staphylococcus aureus environmental surface and pet colonization in households of children with community-associated methicillin-resistant S. aureus (CA-MRSA) infection.Methods-Between 2012 and 2015, 150 children with CA-MRSA infections and their household contacts and pets were enrolled in this cross-sectional study in metropolitan Saint Louis, MO. Cultures to detect S. aureus were collected from 3 anatomic sites of household members, 2 dog/cat sites, and 21 environmental surfaces in each household. Molecular epidemiology of S. aureus isolates was determined via repetitive-sequence PCR. Generalized linear models were developed to identify factors associated with S. aureus/MRSA household contamination.

This study identified practices that correlate with MRSA colonization, which will inform physician counseling and multifaceted interventions among MRSA-affected households to mitigate MRSA in the community.

Abstract Background A household approach to decolonization decreases skin and soft tissue infection (SSTI) incidence, though this is burdensome and costly. As prior SSTI increases risk for SSTI, we hypothesized that the effectiveness of decolonization measures to prevent SSTI when targeted to household members with prior year SSTI would be noninferior to decolonizing all household members. Methods Upon completion of our 12-month observational Household Observation of Methicillin-resistant Staphylococcus aureus in the Environment (HOME) study, 102 households were enrolled in HOME2, a 12-month, randomized noninferiority trial. Pediatric index patients with community-associated methicillin-resistant Staphylococcus aureus (MRSA) SSTI, their household contacts, and pets were enrolled. Households were randomized 1:1 to the personalized (decolonization performed only by household members who experienced SSTI during the HOME study) or household (decolonization performed by all household members) approaches. The 5-day regimen included hygiene education, twice-daily intranasal mupirocin, and daily bleach-water baths. At 5 follow-up visits in participants’ homes, swabs to detect S. aureus were collected from participants, environmental surfaces, and pets; incident SSTIs were ascertained. Results Noninferiority of the personalized approach was established for the primary outcome 3-month cumulative SSTI: 23 of 212 (10.8%) participants reported SSTI in household approach households, while 23 of 236 (9.7%) participants reported SSTI in personalized approach households (difference in proportions, −1.1% [95% confidence interval, −6.7% to 4.5%]). In multivariable analyses, prior year SSTI and baseline MRSA colonization were associated with cumulative SSTI. Conclusions The personalized approach was noninferior to the household approach in preventing SSTI. Future studies should interrogate longer durations of decolonization and/or decontamination of the household environment to reduce household MRSA burden. Clinical Trials Registration NCT01814371.