Effect of systemic antibiotics and topical chlorhexidine on meticillin-resistant Staphylococcus aureus carriage in...

Area of Science:

• Infectious Diseases
• Microbiology
• Clinical Pharmacy

Background:

• Meticillin-resistant Staphylococcus aureus (MRSA) poses a significant threat in intensive care units (ICUs).
• The influence of antibiotics and antiseptics on MRSA carriage is complex, especially with polypharmacy.
• Understanding within-host dynamics is crucial for effective MRSA transmission control.

Purpose of the Study:

• To investigate the impact of systemic antibiotics and topical chlorhexidine (CHX) on short-term MRSA carriage dynamics in ICU patients.
• To analyze the transition between MRSA-positive and MRSA-negative states based on antimicrobial and antiseptic use.

Main Methods:

• Analysis of longitudinal data from 544 MRSA carriers in an ICU setting.
• Utilized Markov models to assess patient transitions between MRSA carriage states.
• Correlated daily antibiotic and antiseptic prescribing data with MRSA screening results.

Main Results:

• Topical CHX significantly increased the transition from MRSA-positive to MRSA-negative states.
• Evidence suggested CHX also decreased the rate of MRSA reacquisition (negative to positive transition).
• Systemic antibiotics demonstrated weak and inconsistent effects on MRSA carriage transitions.

Conclusions:

• Topical CHX is a promising agent for reducing MRSA carriage in ICUs.
• Systemic antibiotics appear to have a limited role in modulating short-term MRSA carriage dynamics.
• Further research is needed to generalize these findings across different clinical settings.