Utility of prior screening for methicillin-resistant Staphylococcus aureus in predicting resistance of S. aureus infections.
CMAJ
; 185(15): E725-30, 2013 Oct 15.
Article
en En
| MEDLINE
| ID: mdl-24016794
ABSTRACT
BACKGROUND:
Screening for methicillin-resistant Staphylococcus aureus (MRSA) is intended to reduce nosocomial spread by identifying patients colonized by MRSA. Given the widespread use of this screening, we evaluated its potential clinical utility in predicting the resistance of clinical isolates of S. aureus.METHODS:
We conducted a 2-year retrospective cohort study that included patients with documented clinical infection with S. aureus and prior screening for MRSA. We determined test characteristics, including sensitivity and specificity, of screening for predicting the resistance of subsequent S. aureus isolates.RESULTS:
Of 510 patients included in the study, 53 (10%) had positive results from MRSA screening, and 79 (15%) of infecting isolates were resistant to methicillin. Screening for MRSA predicted methicillin resistance of the infecting isolate with 99% (95% confidence interval [CI] 98%-100%) specificity and 63% (95% CI 52%-74%) sensitivity. When screening swabs were obtained within 48 hours before isolate collection, sensitivity increased to 91% (95% CI 71%-99%) and specificity was 100% (95% CI 97%-100%), yielding a negative likelihood ratio of 0.09 (95% CI 0.01-0.3) and a negative predictive value of 98% (95% CI 95%-100%). The time between swab and isolate collection was a significant predictor of concordance of methicillin resistance in swabs and isolates (odds ratio 6.6, 95% CI 1.6-28.2).INTERPRETATION:
A positive result from MRSA screening predicted methicillin resistance in a culture-positive clinical infection with S. aureus. Negative results on MRSA screening were most useful for excluding methicillin resistance of a subsequent infection with S. aureus when the screening swab was obtained within 48 hours before collection of the clinical isolate.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Infecciones Estafilocócicas
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Staphylococcus aureus Resistente a Meticilina
Tipo de estudio:
Diagnostic_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
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Screening_studies
Límite:
Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
CMAJ
Asunto de la revista:
MEDICINA
Año:
2013
Tipo del documento:
Article