Predicting methicillin resistance among community-onset Staphylococcus aureus bacteremia patients with prior healthcare-associated exposure

• Published in: European journal of clinical microbiology & infectious diseases 2012-10, Vol.31 (10), p.2727-2736
• Main Authors: Chen, S.-Y., Chiang, W.-C., Ma, M. H.-M., Hsueh, P.-R., Chang, S.-C., Fang, C.-C., Chen, S.-C., Chen, W.-J., Chie, W.-C., Lai, M.-S.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotic resistance; Antibiotics; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimicrobial agents; Bacteremia - drug therapy; Bacteremia - epidemiology; Bacteremia - microbiology; Bacterial diseases; Bacterial sepsis; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Community-Acquired Infections - drug therapy; Community-Acquired Infections - microbiology; Comorbidity; Cross Infection - drug therapy; Cross Infection - microbiology; Drug resistance; Emergency medical care; Female; Health care; Hospitals; Human bacterial diseases; Humans; Indexing in process; Infectious diseases; Internal Medicine; Long term health care; Male; Medical Microbiology; Medical sciences; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - pathogenicity; Microbial Sensitivity Tests; Middle Aged; Mortality; Nosocomial infections; Patients; Pharmacology. Drug treatments; Physicians; Predictive Value of Tests; Prevalence; Preventive medicine; Retrospective Studies; Risk Factors; Sensitivity and Specificity; Staphylococcal Infections - drug therapy; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococcal infections, streptococcal infections, pneumococcal infections; Staphylococcus infections; Taiwan - epidemiology; Young Adult
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-012-1621-y

To develop and validate prediction rules to identify the risk of methicillin-resistant Staphylococcus aureus (MRSA) infection among community patients who have healthcare-associated (HA) exposure and S. aureus bacteremia. A total of 1,166 adults with community-onset S. aureus bacteremia were retrospectively enrolled. The background prevalence of community MRSA infection was extrapolated from 392 community-associated S. aureus bacteremia (CA-SAB) patients without HA exposure. Complete and clinical risk scores were derived and tested using data from 774 healthcare-associated S. aureus bacteremia (HA-SAB) patients. The risk scores were modeled with and without incorporating previous microbiological data as a model predictor and stratified patients to low-, intermediate-, and high-risk groups for MRSA infection. The clinical risk score included five independent predictors and the complete risk score included six independent predictors. The clinical and complete risk scores stratified 32.7 % and 42.0 % of HA-SAB patients to the low-risk group for MRSA infection respectively. The prevalence of MRSA infection in score-stratified low-risk groups ranged from 16.3 % to 23.3 %, comparable to that of CA-SAB patients (13.8 %). Simple decision rules allow physicians to stratify the risk of MRSA infection when treating community patients with prior HA exposure and possible S. aureus infection.