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Published on: September 5, 2013
Prevalence of oral methicillin-resistant Staphylococcus aureus in an institutionalized veterans population
Abstract:
Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen now of great concern in nursing homes and other institutional settings. MRSA has been well-documented to inhabit the nares, skin wounds, and respiratory tract, but little is known about its presence in the oral cavity. In this study, all patients admitted to an 80-bed VA extended care facility were cultured weekly for 12 weeks to detect the presence of MRSA in the nares, wounds, in-dwelling devices, and the oral cavity. Of a total of 107 participating subjects, 20 cultured positive for oral MRSA, yielding a prevalence of 18.7%, compared with 19.6% prevalence in the nares--the traditionally accepted screening site for MRSA. There was a 91.6% agreement between oral and nasal carriage in subjects, but four of 107 subjects (3.7%) cultured positive for oral MRSA without evidence of nasal carriage. These results suggest that oral MRSA may be more common than previously thought in high-risk settings, with a prevalence comparable with that of nasal infection. Further investigation is necessary to characterize the factors associated with the presence of MRSA in the oral cavity.
Insights
Oral methicillin-resistant Staphylococcus aureus (MRSA) is common in extended care facilities, with prevalence similar to nasal MRSA. Some patients carried oral MRSA without nasal colonization, highlighting the oral cavity as a potential reservoir.
Area of Science:
- Infectious Diseases
- Microbiology
- Geriatric Medicine
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) is a significant nosocomial pathogen.
- MRSA is commonly found in nares, wounds, and respiratory tracts.
- The prevalence and significance of MRSA in the oral cavity are not well understood.
Purpose of the Study:
- To investigate the prevalence of MRSA in the oral cavity of patients in an extended care facility.
- To compare oral MRSA prevalence with nasal MRSA prevalence.
- To identify oral MRSA carriage independent of nasal carriage.
Main Methods:
- Weekly cultures for MRSA over 12 weeks in an 80-bed VA extended care facility.
- Culturing sites included nares, wounds, in-dwelling devices, and the oral cavity.
- 107 subjects participated in the study.
Main Results:
- Oral MRSA was detected in 18.7% of subjects (20/107).
- Nasal MRSA prevalence was 19.6%.
- 91.6% agreement between oral and nasal carriage was observed, but 3.7% had oral MRSA without nasal carriage.
Conclusions:
- Oral MRSA prevalence is comparable to nasal MRSA in high-risk settings.
- The oral cavity may serve as a reservoir for MRSA.
- Further research is needed to understand factors associated with oral MRSA carriage.
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