title: USA300 methicillin-resistant Staphylococcus aureus bacteremia and the risk of severe sepsis: is USA300 methicillin-resistant Staphylococcus aureus associated with more severe infections?
abstract: USA300 methicillin-resistant Staphylococcus aureus (MRSA) is increasing as a cause of severe community-associated bacteremic infections. We assessed severe sepsis in response to infection in patients with USA300 MRSA compared to non-USA300 MRSA bacteremia. A cohort study was conducted from 1997 to 2008 comparing sepsis in response to infection in 271 patients with MRSA bacteremia from 4 VA hospitals. Sixty-seven (25%) patients with MRSA bacteremia were USA300 MRSA; 204 (75%) were non-USA300 MRSA. The proportion of MRSA bacteremia caused by USA300 MRSA increased over time (χ² P < 0.0001). Adjusting for age and nosocomial infection, patients with USA300 MRSA bacteremia were more likely to have severe sepsis or septic shock in response to infection than patients with non-USA300 MRSA bacteremia (adjusted relative risk = 1.82; 95% confidence interval, 1.16-2.87; P = 0.01). This suggests that patients with USA300 MRSA are more likely to develop severe sepsis in response to their infection, which could be due to host or bacterial differences.
authors.affiliation: University of Maryland Baltimore, Baltimore, MD 21201, USA. kris03222001@yahoo.com
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Kreisel
authors.forename: O Colin
authors.initials: OC
authors.lastname: Stine
authors.forename: J Kristie
authors.initials: JK
authors.lastname: Johnson
authors.forename: Eli N
authors.initials: EN
authors.lastname: Perencevich
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Shardell
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Lesse
authors.forename: Fred M
authors.initials: FM
authors.lastname: Gordin
authors.forename: Michael W
authors.initials: MW
authors.lastname: Climo
authors.forename: Mary-Claire
authors.initials: MC
authors.lastname: Roghmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015373:Bacterial Typing Techniques; D015331:Cohort Studies; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D018805:Sepsis / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology*; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology*; D014481:United States