Takamitsu Kodama

Positive clinical risk factors predict a high rate of methicillin-resistant Staphylococcus aureus colonization in emergency department patients.

BACKGROUND This study was undertaken to determine the rate of methicillin-resistant Staphylococcus aureus (MRSA) colonization predicted by clinical risk factors compared with determination by nasal swab culture and polymerase chain reaction in emergency department patients. METHODS From November 2009 to March 2011, patients seen in the emergency department were studied prospectively. The risk of MRSA colonization was determined by clinical risk factors, and both surveillance cultures and a polymerase chain reaction assay were performed in each patient. RESULTS A total of 277 patients was enrolled, and 31.4% (87/277) of patients had a positive surveillance culture or a MRSA polymerase chain reaction assay. The rate of colonization in patients with high-risk factors included the following: past history of colonization/infections, 60.0%; history of previous antibiotic use, 47.2%; more than 30 days hospitalization in the past 3 months, 43.9%; more than 10 days hospitalization in the past 3 months, 41.7%; and a history of hospitalization because of acute illness, 40.0%. CONCLUSION The prevalence rate of colonization in patients with a high risk of MRSA colonization exceeded 30%. Active surveillance cultures should be considered in patients at high risk for MRSA colonization.

Efficacy of serum semi-quantitative procalcitonin measurement kit PCT-Q□ for bacteremia

Background: Serum procalcitonin (PCT) concentration has been used as a specific biomarker for diagnosis and severity of the bacterial infections. Although data of quantitative PCT concentration for bacterial infections have been accumulated, clinical implications for semi-quantitative PCT concentration have not been well defined. Thus, we report the clinical utility of PCT-Q especially for cases with bacteremia. Methods: PCT-Q concentration was measured in those who were suspected bacterial infections among all patients who were evaluated in our Emergency Department from September 2007 to March 2008. PCT-Q concentration was divided into four classes (<0.5, > = 0.5, > = 2.0, > = 10.0ng/mL) and above 0.5ng/mL that was the cut-off value were defined as bacterial infections. We compared the results of PCT-Q with quantitative PCT concentration, white blood cells (WBC) and C-reactive protein (CRP). The results of blood culture of all recruited patients were collected and the results of PCT-Q positive for bacteremia were also analyzed. Furthermore we compared the rates of detection of Methicillin-resistant Staphylococcus aureus (MRSA) in this period with that of previous one year. Results: A total of 291 patients among all 16,700 patients were evaluated. The concentration between PCT-Q and quantitative PCT were almost concordant. Discordance between PCT-Q concentration and WBC was observed, while significant correlation between PCT-Q concentration and CRP concentration was obtained. The sensitivity and specificity of PCT-Q among patients with bacteremia was 72.1% and 64.4%, respectively. The rate of detection of MRSA fell from 6.5% (50/766) to 3.8% (29/773). Conclusion: PCT-Q is useful for diagnosing severe bacterial infections including bacteremia. PCT-Q could be useful to restrain from the emergence of bacterial resistant strains by decreasing unnecessary antimicrobial usage.