Korean J Intern Med.  2019 Jan;34(1):184-194. 10.3904/kjim.2016.351.

Clinical and microbiological factors associated with early patient mortality from methicillin-resistant Staphylococcus aureus bacteremia

• Kim T
• Chong YP
• Park KH
• Bang KM
• Park SJ
• Kim SH
• Jeong JY
• Lee SO
• Choi SH
• Woo JH
• Kim YS

• KMID: 2452502
• DOI: http://doi.org/10.3904/kjim.2016.351

Abstract

BACKGROUND/AIMS
Methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) is a major bloodstream infection with a high mortality rate. Identification of factors associated with early mortality in MRSAB patients would be useful for predicting prognosis and developing new therapeutic options.
METHODS
A prospective cohort of MRSAB patients was examined between August 2008 and June 2011. Early and late mortality was defined as death within 2 and 28 days of blood culture, respectively. The clinical and microbiological characteristics in the early and late mortality and survival groups were compared. Risk factors associated with severe sepsis or septic shock were also investigated.
RESULTS
A total of 385 adult MRSAB patients whose S. aureus isolates were available were enrolled; of these patients, 25 patients (6.5%) and 50 (13%) died early and late, respectively. Compared with both the late-mortality group and the survival group, severe sepsis or septic shock was a statistically significant independent risk factor associated with early mortality. Rapidly or ultimately fatal McCabe and Jackson classification (adjusted odds ratio [aOR], 1.94; 95% confidence interval [CI], 1.25 to 3.02) and pneumonia (aOR, 2.04; 95% CI, 1.03 to 4.02) were independently associated with severe sepsis or septic shock. A vancomycin minimum inhibitory concentration (MIC) ≥ 1.5 μg/mL was associated with a reduced incidence of severe sepsis or septic shock (aOR, 0.53; 95% CI, 0.34 to 0.84).
CONCLUSIONS
Severity of illness seems to be the most important risk factor associated with early mortality in MRSAB. Although vancomycin MIC was not independently associated with early mortality, reduced vancomycin susceptibility appears to be linked to reduced disease severity.

Keyword

Methicillin-resistant Staphylococcus aureus; Bacteremia; Risk factors; Mortality

MeSH Terms

Adult
Bacteremia*
Classification
Cohort Studies
Humans
Incidence
Methicillin Resistance*
Methicillin-Resistant Staphylococcus aureus*
Microbial Sensitivity Tests
Mortality*
Odds Ratio
Pneumonia
Prognosis
Prospective Studies
Risk Factors
Sepsis
Shock, Septic
Vancomycin
Vancomycin