Comparison of both clinical features and mortality risk associated with bacteremia due to community-acquired methicillin-resistant Staphylococcus aureus and methicillin-susceptible S. aureus.
BACKGROUND
The majority of research about community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection has focused on skin and soft-tissue infections. No literature has been published on the clinical features and outcomes of adult patients with CA-MRSA bacteremia in comparison with patients with community-acquired methicillin-susceptible S. aureus (CA-MSSA) bacteremia.


METHODS
From 1 January 2001 through 31 December 2006, the demographic data and outcome of 215 consecutive adult patients admitted to a tertiary care center in Taiwan with S. aureus bacteremia (age, >16 years) who fulfilled the criteria for community-acquired S. aureus bacteremia were collected for analysis.


RESULTS
The mean age (+/-SD) was 56.8+/-20.5 years. There were 30 patients (14%) with CA-MRSA bacteremia and 185 (86%) patients with CA-MSSA bacteremia. Cutaneous abscess (odds ratio, 5.46; 95% confidence interval, 1.66-17.94) and necrotizing pneumonia (odds ratio, 24.81; 95% confidence interval, 2.63-234.03) were the independent predictors of CA-MRSA bacteremia; endovascular infection was the only independent predictor of CA-MSSA bacteremia. After Cox regression analysis, the independent significant risk factors for 30-day mortality included increased age, shock, and thrombocytopenia (<100,000 cells/microL). After adjustment, the day 30 mortality of patients with CA-MRSA bacteremia was not significantly higher than that of patients with CA-MSSA bacteremia (adjusted hazard ratio, 1.01; 95% confidence interval, 0.30-3.39; P = .986). Most (92%) of 25 available CA-MRSA isolates were multilocus sequence typing 59.


CONCLUSIONS
The number of adult patients with CA-MRSA bacteremia increased with time, and the disease was associated with more necrotizing pneumonia and cutaneous abscess but less endovascular infection than was CA-MSSA bacteremia. Patients with CA-MRSA bacteremia did not have higher mortality than did patients with CA-MSSA, even though most of the patients with CA-MRSA bacteremia did not receive empirical glycopeptide therapy.
Wang
Jiun-Ling
JL
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Chen
Shey-Ying
SY
Wang
Jann-Tay
JT
Wu
Grace Hui-Min
GH
Chiang
Wen-Chu
WC
Hsueh
Po-Ren
PR
Chen
Yee-Chun
YC
Chang
Shan-Chwen
SC
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology / Q000401:mortality / Q000503:physiopathology; D017714:Community-Acquired Infections / Q000382:microbiology / Q000401:mortality / Q000503:physiopathology; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008712:Methicillin / Q000494:pharmacology*; D016106:Methicillin Resistance; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000382:microbiology / Q000401:mortality; D013211:Staphylococcus aureus / Q000187:drug effects / Q000472:pathogenicity; D013624:Taiwan / Q000453:epidemiology
D000900:Anti-Bacterial Agents; D008712:Methicillin