Effect of systemic antibiotics and topical chlorhexidine on meticillin-resistant Staphylococcus aureus carriage in intensive care unit patients

• Published in: The Journal of hospital infection Vol. 79; no. 3; pp. 222 - 226
• Main Authors: Kypraios, T, O’Neill, P.D, Jones, D.E, Ware, J, Batra, R, Edgeworth, J.D, Cooper, B.S
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2011; Elsevier
• Subjects: Administration, Topical; Anti-Bacterial Agents - administration & dosage; Anti-Bacterial Agents - pharmacology; Anti-Infective Agents, Local - administration & dosage; Anti-Infective Agents, Local - pharmacology; Antibacterial agents; Antibiotics; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiseptics; Bacterial diseases; Bayesian analysis; Biological and medical sciences; Carrier State - drug therapy; Carrier State - microbiology; Chlorhexidine; Chlorhexidine - administration & dosage; Chlorhexidine - pharmacology; Culture Media; Human bacterial diseases; Humans; Infectious Disease; Infectious diseases; Intensive Care Units; Markov chain; Markov Chains; Medical sciences; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Meticillin-resistant Staphylococcus aureus; Nasal Cavity - microbiology; Odds Ratio; Pharmacology. Drug treatments; Staphylococcal Infections - drug therapy; Staphylococcal Infections - microbiology; Staphylococcal infections, streptococcal infections, pneumococcal infections; Staphylococcus aureus; Treatment Outcome; Markov chain; Chlorhexidine; Antibiotics; Antiseptics; Bayesian analysis; Meticillin-resistant Staphylococcus aureus; Intensive care unit; Local administration; Biguanides; Bacteria; Micrococcales; Micrococcaceae; Disseminated; Public health; Staphylococcus aureus; Human; Guanidines; Infection; Antibiotic; Antiseptic; Bacteriosis; Antibacterial agent; Disinfecting agent; Staphylococcal infection; Colonization
• ISSN: 0195-6701; 1532-2939
• DOI: 10.1016/j.jhin.2011.05.008

Summary Antibiotics and antiseptics have the potential to influence carriage and transmission of meticillin-resistant Staphylococcus aureus (MRSA), although effects are likely to be complex, particularly in a setting where multiple agents are used. Here admission and weekly MRSA screens and daily antibiotic and antiseptic prescribing data from 544 MRSA carriers on an intensive care unit (ICU) are used to determine the effect of these agents on short-term within-host MRSA carriage dynamics. Longitudinal data were analysed using Markov models allowing patients to move between two states: MRSA positive (detectable MRSA carriage) and MRSA negative (no detectable carriage). The effect of concurrent systemic antibiotic and topical chlorhexidine (CHX) on movement between these states was assessed. CHX targeted to MRSA screen carriage sites increased transition from culture positive to negative and there was also weaker evidence that it decreased subsequent transition from negative back to positive. In contrast, there was only weak and inconsistent evidence that any antibiotic influenced transition in either direction. For example, whereas univariate analysis found quinolones to be strongly associated with both increased risk of losing and then reacquiring MRSA carriage over time intervals of one day, no effect was seen with weekly models. Similar studies are required to determine the generalisability of these findings.