Outbreak interventions for drug-resistant bugs

Caveats and controversies dog many approaches

The Centers for Disease Control and Prevention’s new draft infection control guidelines include a review of the pros and cons of control strategies to deal with a suspected or confirmed outbreak of multi-drug-resistant pathogens.1 The list includes the following summarized highlights:

Surveillance Measures

1. Screening cultures: patients/residents, including new admissions; health care workers if implicated in transmission or carriage.

  • expensive, time-consuming, and requires laboratory support
  • utilized to define scope of problem and reservoir as well as candidates for enhanced pre- cautions and/or decolonization therapy

2. Molecular typing of isolates from colonized/ infected (C/I) patients.

  • technology may not be available
  • results may not be timely
  • expensive, but offers best evidence for presence of an outbreak

Control Measures

1. Contact precautions for C/I patients.

  • necessitates screening to identify all candidates
  • uncertain benefit without timely recognition of C/I patients
  • logistics often difficult
  • difficult to achieve adherence

2. Contact precautions for all C/I new patients entering health care setting and all newly recognized carriers.

  • often impractical
  • requires space, screening, and possibly additional staffing
  • adverse effect of desired socialization in some settings
  • most useful for control of hyperendemic and/or clinically problematic pathogens

3. Cohort C/I patients.

  • necessitates screening to identify all candidates
  • logistics often difficult
  • impractical when multidrug-resistant organism (MDRO) prevalence rates are high

4. Establish isolation areas or wards.

  • seldom practical
  • implies commitment to screening cultures for all new arrivals
  • requires space, additional staffing
  • adverse effect of desired socialization in some settings

5. Cohort health care workers.

  • difficult in most settings;
  • may require screening cultures of all staff
  • increases staffing requirements

6. Enhanced environmental decontamination.

  • considered for management of vancomycin-resistant enterococci (VRE) cases in acute care
  • benefit in reducing transmission unproven

Reduction of Reservoir

1. Exclusion of C/I patients from facility.

  • strategy used by some long-term care facilities
  • not widely recommended
  • may negatively impact care and create hardships for patients

2. Early discharge of C/I patients.

  • may provide benefit in acute care facilities but unproven
  • not applicable in other care settings

3. Decolonization therapy of patients/residents, new admissions, and staff.

  • no agent for VRE or highly resistant gram-negative bacilli
  • not 100% effective for methicillin-resistant Staphylococcus aureus and development of resistance to agent(s) used common
  • screening cultures required

Reference

1. Strausbaugh L, Jackson M, Rhinehart, et al and the Centers for Disease Control and Prevention Healthcare Infection Control Practices Advisory Committee. Guideline to Prevent Transmission of Infectious Agents in Healthcare Settings 2002. Draft #2. Feb. 15, 2002.