Risk Factors for Persistent Carriage of Methicillin‐ResistantStaphylococcus aureus

Abstract

We determined risk factors associated with persistent carriage of methicillin-resistant Staphylococcus aureus (MRSA) among 102 patients enrolled in a double-blind, placebo-controlled trial of nasally administered mupirocin ointment. MRSA decolonization was unsuccessful in 77 (79%) of 98 patients who met the criteria for evaluation. By univariate analysis, 4 variables were found to be associated with persistent MRSA colonization (P < .1 for all 4): absence of mupirocin treatment, previous fluoroquinolone therapy, > or = 2 MRSA-positive body sites, and low-level mupirocin resistance. After multivariable Cox proportional hazards modeling, the presence of > or = 2 positive body sites (adjusted hazard ratio [AHR], 1.7; 95% confidence interval [CI], 1.0-2.9) and previous receipt of a fluoroquinolone (AHR, 1.8; 95% CI, 1.0-3.3) were independently associated with MRSA persistence, whereas nasal mupirocin tended to confer protection (AHR, 0.6; 95% CI, 0.4-1.0). Low-level mupirocin resistance was observed in 9 genotypically different MRSA strains and was not independently associated with chronic MRSA carriage (AHR, 1.5; 95% CI, 0.9-2.5). Our findings suggest that multisite MRSA carriage and previous receipt of a fluoroquinolone are independent risk factors for persistent MRSA colonization.

Clinical impact of MRSA in a stem cell transplant unit: analysis before, during and after an MRSA outbreak

“…In addition, the use of prophylactic ciprofloxacin on the non-transplant ward was suspended as the strains seen were universally resistant and ciprofloxacin is known to select for, and prolong the carriage of, MRSA. [11][12][13] A striking feature in these patients is the very high incidence of invasive MRSA infections, which has not been previously reported. This was particularly noted in, but not confined to, the outbreak period.…”

Control of Methicillin-Resistant Staphylococcus aureus in a Tertiary Hospital with Low Background Endemicity: Evidence That Interventions Do Work

“…7 Until recently, HCWs have been screened for MRSA colonization prior to commencing employment, and those found to be colonized were decolonized before starting work in a clinical care area. From April 2004 to April 2007, only 55 (1.3%) of 4,280 newly employed HCWs were found to be colonized with MRSA; this low number, as well as the lack of supporting evidence for the benefit of decolonization, led us to discontinue this practice.…”

Methicillin-ResistantStaphylococcus aureusControl: We Didn't Start the Fire, but It's Time to Put It Out

“…34 Colonization at sites other than the nose was, as might be expected, a risk factor for persistent carriage despite the therapy. 42 Although mupirocin-resistant strains had not yet spread through the Brazilian population studied by Sandri et al, ' 3 it is worth noting that mupirocin has been shown to be ineffective for reliable eradication of mupirocin-resistant strains, 43 although one study suggested that it might sometimes be useful in that situation. 44 Multiple studies have reported the arrival (or development) and spread of mupirocinresistant strains in settings where mupirocin is in frequent use, 45,46 including multiple reports of resistant strains spreading in Brazilian hospitals.…”