Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have been observed to cluster in households. However, the interplay of household colonization pressure and transmission, hygiene and behavioral risk factors, and household environmental contamination influencing CA-MRSA colonization and infection has not been elucidated. These risk factors must be defined to develop evidence- based guidelines to interrupt CA-MRSA transmission and prevent infections. Understanding the impact of these variables will inform practice to improve health and decrease the burden of CA-MRSA colonization and disease.
The aims of the HOME study are to:
Define the transmission dynamics of CA-MRSA colonization and infection among pediatric index patients and their household contacts over one year, and determine the contribution of CA-MRSA colonization to subsequent CA-MRSA infection.
Identify hygiene and behavioral practices contributing to CA-MRSA transmission, colonization, and infection within house.
Determine the role of environmental contamination and household characteristics in household CA-MRSA transmission.
The central hypothesis of this study is that modifiable risk factors contribute to the dynamics of CA-MRSA colonization, infection, and transmission among household members. The HOME study is a one-year prospective cohort study that will enroll 135 pediatric patients with CA-MRSA infection and their household members. This study will be performed at St. Louis Children’s Hospital and in collaboration with physicians affiliated with the Washington University Pediatric and Adolescent Ambulatory Research Consortium (WU PAARC), a practice-based research network.
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections cluster in households and can be transferred among household members. Household members with asymptomatic CA-MRSA colonization may serve as reservoirs for transmission. To reduce the incidence of CA-MRSA skin and soft tissue (SSTI) infection, decolonization protocols, generally consisting of topical antimicrobials, are frequently prescribed to patients and their household contacts. As decolonization measures are cumbersome, targeting only household members at greatest risk for recurrent SSTI would decrease the burden and cost of performing these measures, and increase adherence to these protocols.
The goal of the HOME 2 study is to compare the effectiveness of commonly used decolonization treatments when performed by individuals within a household with a history of SSTI in the prior year in comparison to decolonization of all household members in preventing SSTI over a one year period. The central hypothesis of this study is that an individualized approach will be equally as effective as decolonization of all household members to prevent SSTI.
The HOME 2 study is a one year clinical trial that will enroll 100 pediatric patients with a history of CA-MRSA SSTI and their household members. This study will be performed at St. Louis Children’s Hospital and in collaboration with physicians affiliated with the Washington University Pediatric and Adolescent Ambulatory Research Consortium (WU PAARC), a practice-based research network.
Staphylococcus aureus is the most common cause of skin and soft tissue infections (SSTI). The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) epidemic has complicated empiric antibiotic therapy for SSTI. The Centers for Disease Control and Prevention and the Infectious Diseases Society of America have published guidelines for treatment of CA-MRSA SSTI which generally recommend use of oral antibiotics such as clindamycin (Clinda) or trimethoprim-sulfamethoxazole (TMP-SMX) when MRSA is the suspected cause of infection. However, data regarding the efficacy and necessity of these agents for treatment of CA-MRSA SSTI is lacking.
The aim of this trial is to provide a clinically relevant treatment strategy for uncomplicated SSTIs in children and adults. Participants with a drainable skin abscess will be enrolled in this trial and randomized to receive 10 days of treatment with Clinda, TMP-SMX, or a placebo. The primary objective of this trial is to compare the cure rate of drained SSTIs in patients randomized to receive Clina, TMP-SMX, or placebo, and test the hypothesis that the groups will have a similar rate of cure over a six week period. Approximately 1,300 adult and child participants will be enrolled for this trial, currently taking place here at Washington University, as well as at 5 other medical centers across the country in Chicago, Los Angeles, San Francisco, Nashville, and Atlanta.
Colonization with strains of community-acquired MRSA (CA-MRSA) is a risk factor for subsequent skin and soft tissue infection. Methods of MRSA decolonization have not been studied in this patient population. This study is a randomized controlled trial with four intervention arms to determine the ideal strategy for eradication of CA-MRSA.
The intervention arms are 1) intensive education on prevention of skin infections through improvements in personal hygiene, 2) education plus application of mupirocin in the nasal mucosa alone, 3) a combination of education, nasal application of mupirocin and chlorhexidine showers, and 4) a combination of education, nasal application of mupirocin and bathing in dilute bleach water.
Outcome measures include the proportion of patients in all four study arms in whom CA-MRSA has been eradicated and the rate of recurrence of CA-MRSA infections among these patients. We hypothesize that decolonization with mupirocin ointment and chlorhexidine showers or dilute bleach baths are likely to be more successful than either the application of nasal mupirocin ointment alone or hygiene and education measures alone. This study is critical to the development of enhanced, evidence-based treatment and prevention strategies.
Colonization with CA-MRSA is a risk factor for subsequent skin and soft tissue infections. Eradication of this organism from the nose or skin may prevent the development of future SSTI. Transmission of CA-MRSA within households has been reported, but the significance of colonization in household members in relation to the effectiveness of decolonization efforts in a patient with a CA-MRSA infection is unknown.
The goal of this study is to evaluate the efficacy of decolonization measures, specifically improved hygiene measures, mupirocin nasal ointment, and chlorhexidine antiseptic, performed by an entire household versus measures directed at the index patient alone. We hypothesize that efforts to eradicate CA-MRSA carriage from the index patient will be twice as effective when decolonization measures are performed by the entire household than measures performed by the index patient alone. The primary outcome measure will be eradication of S. aureus carriage 1 month after performing decolonization measures. Secondary outcomes will be colonization status 3, 6 and 12 months after performing decolonization measures, length of decolonization or time to recolonization, and development of a recurrent SSTI.
This trial will enroll 180 patients (90 per arm) and follow their colonization status and incidence of infection for one year. This study will be performed in collaboration with physicians affiliated with the Washington University Pediatric and Adolescent Ambulatory Research Consortium (WU PAARC), a pediatric practice-based research network.
Many CA-MRSA isolates carry the co-transcribed genes lukS-PV and lukF-PV, which encode the components of Panton-Valentine leukocidin (PVL), a pore-forming, leukocyte-destroying exotoxin. PVL is produced by many CA-MRSA strains that cause cutaneous and invasive disease. However, our understanding of the relationship between specific bacterial virulence factors, host immune responses, and the outcomes of community acquisition of MRSA are generally unknown.
STIR is a pilot prospective cohort study to investigate the anti-PVL antibody response to human colonization or infection with CA-MRSA and the relationship of this adaptive response to the development of subsequent infection. We hypothesize that individuals who generate an antibody response to toxins implicated in the pathogenesis of CA-MRSA infection, upon colonization or initial cutaneous infection, may be protected against future cutaneous or invasive infections. Defining the extent and significance of human antibody response to the PVL toxin produced by CA-MRSA will inform future studies critical to understanding the clinical behavior of CA-MRSA, leading to enhanced treatment and prevention strategies.