For Infection Control Professionals – Household Contacts Study
Study: Spread of Community-Associated MRSA Among Household Contacts
Outbreaks of infection among individuals in close contact (e.g., sports teams, incarcerated populations, anecdotal observations) have suggested that community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) can easily spread from person to person. However, few data are available that define MRSA carriage rates and symptomatic disease among household contacts of index patients.
Primary Study Objectives
- To prospectively define colonization and infection rates among household contacts of index patients with CA-MRSA infection compared with infection rates associated with other pathogenic S. aureus strains (CA-MSSA, HA-MRSA, HA-MSSA—see table below); and
- To assess rates of environmental contamination in these households.
Patients, both adults and children, with S. aureus infections at the University of Chicago Medical Center and the Harbor-UCLA Medical Center in Los Angeles and their household contacts. A household contact is a person residing with the index patient or a nonresident who has spent 4 hours per day or more in the home of the index patient for at least 5 of the 7 days proceeding the day of presentation of the index case.
A prospective study that follows patients at the time of enrollment in the study, at study baseline, and again at 3 and 6 months. We enroll patients that come to the study sites with a S. aureus skin infection as index patients. We then contact and enroll index patients' household members. We assess risk factors, infection, and colonization rates among the four S. aureus groups (CA-MRSA, CA-MSSA, HA-MRSA, HA-MSSA—see table below). A list of 10 fomites (inanimate objects) are cultured in each household as well. The study was initiated May 2008 and will enroll patients over a 3-year period.
We enroll patients with S. aureus infections and their household members and ask them to complete a survey of risk factors for S. aureus infection as well as to undergo nasal, throat, and inguinal fold cultures to assess S. aureus colonization. We also swab the household environment of the enrolled participants for S. aureus colonization. Isolates are typed by several molecular techniques.
Principal Investigators and Study Sites
Robert S. Daum, MD, CM, University of Chicago Medical Center
Loren G. Miller, MD, MPH, Los Angeles County Harbor-UCLA Medical Center
National Institutes of Health (NIH); National Institute of Allergy and Infectious Diseases (NIAID)