MRSA Research Center

The University of Chicago Medicine

  • Welcome
  • Patients
  • Clinicians
  • Researchers
  • Education & Training
  • Alumni

For Infection Control Professionals – Dallas County Jail (Texas) Study

Study: MRSA Colonization and Control in the Dallas County Jail

Urban jails are a reservoir for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) bacteria. Outbreaks of CA-MRSA skin and soft tissue infections (SSTIs) have occurred in prisons and jails that house an increasing number of detainees each year in Texas and the United States overall. Many detainees are held for brief periods, being released into the community in the manner of a revolving door. Molecular evidence has linked MRSA isolates from correctional facilities to local CA-MRSA strains. Examining the MRSA epidemic in a large urban jail is a crucial step toward the containment of MRSA in the community at large.

Study Goals

To determine:

  1. the frequency of environmental contamination in the Dallas County Jail ("Jail");
  2. which fomites (environmental surfaces, objects) are most commonly contaminated and which MRSA strains are on them;
  3. the number of detainees at the Jail who carry MRSA in their noses or on their skin and how many become infected or colonized with MRSA while staying at the Jail;
  4. the specific strains of MRSA that come from the nose and skin in detainees with and without skin infections; and
  5. the efficacy of bathing with chlorhexidine gluconate (CHG), a kind of soap, in decreasing the prevalence of MRSA colonization of Jail detainees.

Study population and size

Approximately 2915 male and female detainees >18 years of age.

Study design

The study has 4 phases, all to occur in overlapping periods of time:

  1. Environmental Contamination. We will obtain cultures from various surfaces and objects in Jail tanks to look for MRSA and MSSA (Methicillin-Susceptible Staphylococcus aureus).
  2. Infection Surveillance. For a period of 18 months, we will recruit detainees at Jail clinics who have SSTIs requiring incision and drainage; collect all bacterial isolates of MRSA and MSSA cultured from the subjects by the clinical laboratory used by the Jail; and in the MRSA Research Center Lab perform genetic analyses on the bacteria, comparing strains from the Jail with strains from other groups of patients.
  3. CHG double blind cluster randomized trial.
    1. Up to 60 Jail tanks will be randomized into 3 study groups, for the 6-month trial:
      • Group 1 will receive cloths impregnated with CHG three times per week.
      • Group 2 will receive cloths that look like CHG cloths but contain only water three times per week.
      • Group 3 will receive no skin treatment.
    2. We will obtain cultures (from both nostrils and hands) at enrollment from all subjects and at 8 weeks from 50% of subjects randomly chosen from each Group.
    3. At 13 weeks, we will check whether Group 1 has a different rate of SSTIs than Groups 2 and 3. We will terminate the study at 13 weeks if a significant difference is identified; if not, the study will continue for 26 weeks.
    4. If the study continues, at 26 weeks we will test 50% of subjects in each group for MRSA.
    5. There will be rolling enrollment of newly arriving detainees.
  4. Genetic studies of MRSA isolates. We will conduct genetic studies on the bacteria isolated from environmental surface cultures, clinical infections of detainees treated at the Jail health clinic, and cultures obtained from nostrils and hands.

Study Principal Investigators and sites:

Robert S. Daum, MD, CM, University of Chicago Medical Center
Jane D. Siegel, MD, University of Texas Southwestern Medical Center
Study sponsors: CDC, Sage Products, Inc.

For information on a previous study we carried out at the Cook County Jail (Illinois), please see the poster presentation.