Prevalence of methicillin-resistant Staphylococcus aureus in skin and soft tissue infections in patients presenting to Canadian emergency departments

Abstract

Background:Community-associated methicillin-resistantStaphylococcus aureus(MRSA) is an increasingly common cause of skin and soft tissue infection (SSTI) worldwide. The prevalence of MRSA in SSTIs across Canada has not been well described. Studies in the United States have shown significant geographic variability in the prevalence of MRSA. This study characterizes the geographic prevalence and microbiology of MRSA in patients presenting to Canadian emergency departments with SSTIs.Methods:Using a prospective, observational design, we enrolled patients with acute purulent SSTIs presenting to 17 hospital emergency departments and 2 community health centres (spanning 6 Canadian provinces) between July 1, 2008, and April 30, 2009. Eligible patients were those whose wound cultures grewS. aureus. MRSA isolates were characterized by antimicrobial susceptibility testing and pulsed-field gel electrophoresis. All patients were subjected to a structured chart audit, and patients whose wound swabs grew MRSA were contacted by telephone to gather detailed information regarding risk factors for MRSA infection, history of illness, and outcomes.Results:Of the 1,353S. aureus–positive encounters recorded, 431 (32%) grew MRSA and 922 (68%) wounds grew methicillin-susceptibleS. aureus. We observed significant variation in both the prevalence of MRSA (11–100%) and the proportion of community-associated strains of MRSA (0– 100%) across our study sites, with a significantly higher prevalence of MRSA in western Canada.Interpretation:MRSA continues to emerge across Canada, and the prevalence of MRSA in SSTIs across Canada is variable and higher than previously expected.

Prevalence and factors associated with wound colonization by Staphylococcus spp. and Staphylococcus aureusin hospitalized patients in inland northeastern Brazil: a cross-sectional study

“…In this study, slightly over 30% of the wounds colonized by S. aureus were colonized by MRSA, which is similar to previously reported findings [3,28,30-32]. Even though the present study found a lower rate of wound colonization by S. aureus than in studies conducted in other regions and other countries, the rate of antibiotic resistance was high, which may be attributed to prior antibiotic use by more than a third of the patients, the majority of whom were elderly with comorbidities, and use of multiple antibiotics.…”

Methicillin‐Resistant Staphylococcus aureus Colonization among Health Care Workers in a Downtown Emergency Department in Toronto, Ontario

“…The present study, which found no HCWs in the sample of 89 ED staff to be colonized with MRSA, and 28.1% MSSA colonization, is the first to document the prevalence of MRSA and MSSA colonization in ED HCWs in Canada. These data are compared with the MRSA and MSSA per cent colonized of 1.9% and 25.9%, respectively, documented in the aforementioned cohort study being conducted in the same ED during the study period (10), and at a time when the prevalence of MRSA in SSTIs at this centre was 30% (15). These population percentages of MRSA colonization are also consistent with recent estimates of MRSA colonization in the general population of the United States (9).…”

Characterization of Staphylococcus aureus Isolated from Non-Native Patients with Skin and Soft Tissue Infections in Shanghai

“…aureus particularly CA-MRSA is the predominant cause of SSTIs worldwide[ 20 ].In our study, 22 isolates (18.8%) of 117 isolates were found as MRSA, and it was lower than the occurrences of MRSA among S . aureus SSTIs previously reported[ 1 , 2 , 21 ].Eight MRSA isolates (3 HA-MRSA and 5 CA-MRSA) were found among non-native patients and 14 MRSA isolates (12 HA-MRSA and 2 CA-MRSA) were found among native patients. We found no significant difference between the occurrences of MRSA in non-native patients compared to native patients.…”