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Updated: Jul 11, 2026
Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)
Published on: February 9, 2011
Risk factors associated with methicillin-resistant Staphylococcus aureus infection in patients admitted to the ED
Alain Viallon1, Olivier Marjollet, Philippe Berthelot
1Emergency and Intensive Care Department, Hôpital de Bellevue, Saint-Etienne, France. alain.viallon@chu-st-etienne.fr
Objectives:
The objective of our study was to define the characteristics of patients admitted to the emergency department (ED) presenting with a methicillin-resistant Staphylococcus aureus (MRSA) infection.
Patients And Methods:
The study included all patients admitted to the ED between January 2003 and December 2004 in whom a staphylococcal infection was documented. The risk factors associated with carriage of MRSA, the diagnosis made in the ED, and the treatment administered were established from the patients' medical files. The sites from which the bacteria were isolated, the spectrum of resistance of the staphylococci to different antibiotics, and the presence or absence of the gene coding for Panton-Valentin leukocidin for certain S aureus isolates were determined from the reports issued by the bacteriologic department. Two groups of patients were compared: those with an infection caused by MRSA and those with an infection due to methicillin-susceptible S aureus (MSSA).
Results:
A total of 238 patients were included, 93 presenting with an infection caused by MRSA and 145 an infection due to MSSA. The patients harboring MRSA had a higher median age than those carrying MSSA (74 vs 61 years, P = .0001), experienced a greater loss of autonomy (according to the Knauss index), and had more comorbidity factors. Nine patients, younger than 40 years, presented with an infection due to MRSA in the absence of any comorbidity factor or any factor associated with carriage of these bacteria. Seven patients in the MRSA group were tested for Panton-Valentine leukocidin genes, and a positive result was obtained in 2 of them. Regardless of whether the infection was caused by MRSA or by MSSA, the bacteria were most frequently isolated from a cutaneous site, in 40% and 65% of the patients, respectively. Irrespective of the group, 28% of the patients presented with bacteremia. The spectrum of resistance of these MRSA strains suggested a hospital rather than community origin. The initial antibiotic therapy was rarely appropriate in the case of an infection due to MRSA.
Conclusion:
Infections caused by MRSA accounted for a high proportion of the staphylococcal infections diagnosed in the ED, necessitating a rational approach to the prescription of antibiotics for infections of this type.
Insights
Methicillin-resistant Staphylococcus aureus (MRSA) infections were common in emergency departments. Patients with MRSA infections were older, had more comorbidities, and required more appropriate antibiotic prescribing.
Area of Science:
- Infectious Diseases
- Clinical Microbiology
- Epidemiology
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen causing various infections.
- Understanding the characteristics of patients with MRSA infections is crucial for effective management.
Purpose of the Study:
- To define the demographic and clinical characteristics of patients presenting with MRSA infections in the emergency department (ED).
- To compare patients with MRSA infections to those with methicillin-susceptible Staphylococcus aureus (MSSA) infections.
Main Methods:
- Retrospective study of patients admitted to the ED between January 2003 and December 2004 with documented staphylococcal infections.
- Data collected included risk factors, diagnosis, treatment, bacterial isolation sites, antibiotic resistance patterns, and Panton-Valentine leukocidin (PVL) gene presence.
- Comparison of patients with MRSA versus MSSA infections.
Main Results:
- Of 238 patients, 93 had MRSA and 145 had MSSA infections.
- MRSA patients were older (median 74 vs. 61 years), had greater loss of autonomy, and more comorbidities.
- Cutaneous sites were the most common isolation source for both MRSA (40%) and MSSA (65%). Bacteremia occurred in 28% of patients regardless of MRSA or MSSA.
- MRSA resistance patterns suggested hospital origin, and initial antibiotic therapy was often inappropriate.
Conclusions:
- MRSA infections represent a substantial proportion of staphylococcal infections seen in the ED.
- The findings highlight the need for a rational approach to antibiotic prescribing for staphylococcal infections, particularly in light of MRSA prevalence.
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