title: Correlation between time to positivity of blood cultures with clinical presentation and outcomes in patients with Klebsiella pneumoniae bacteraemia: prospective cohort study.
abstract: Time to positivity (TTP) of blood cultures in patients with bacteraemia is considered to be a predictor of outcome for some bacterial species. Two hundred and thirty-one patients with Klebsiella pneumoniae monomicrobial bacteraemia at a hospital from 1 January to 31 December 2007 were prospectively enrolled. TTP <7 h (46 patients, 19.9%) was associated with a higher Pittsburg bacteraemia score (6.2 +/- 5.5 vs. 3.7 +/- 4.3, p 0.002), fewer non-fatal diseases by the McCabe classification (39.1% vs. 64.9%, p 0.002), a higher percentage of patients with liver cirrhosis, active malignancy, and chemotherapy within 3 months (28.3% vs. 11.9%, p 0.007; 28.3% vs. 14.6%, p 0.031; 23.9% vs. 5.4%, p <0.001), more primary bacteraemia (45.7% vs. 22.2%, p 0.002), and a higher 30-day mortality rate (47.8% vs. 21.1%, p <0.001). Risk factors for 30-day mortality in the univariate analysis included higher Pittsburg bacteraemia score (5.8 +/- 5.3 vs. 3.7 +/- 4.3, p 0.002), primary bacteraemia (41.0% vs. 21.8%, p 0.004), TTP <7 h (36.1% vs. 14.1%, p <0.001), and the presence of active malignancy (29.5% vs. 12.9%, p 0.004). In the multivariate analysis, higher Pittsburg bacteraemia score (OR 1.07; 95% CI 1.01-1.14), TTP <7 h (OR 2.46; 95% CI 1.20-5.05) and active malignancy (OR 2.21; 95% CI 1.03-4.73) were the significant factors associated with 30-day mortality. In the Kaplan-Meier survival curve, short TTP was significantly associated with mortality at all time-points after admission. TTP of blood cultures, interpreted with a cut-off point of <7 h, in patients with K. pneumoniae bacteraemia can provide useful prognostic information.
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: C-H
authors.initials: CH
authors.lastname: Liao
authors.forename: C-C
authors.initials: CC
authors.lastname: Lai
authors.forename: M-S
authors.initials: MS
authors.lastname: Hsu
authors.forename: Y-T
authors.initials: YT
authors.lastname: Huang
authors.forename: F-Y
authors.initials: FY
authors.lastname: Chu
authors.forename: H-S
authors.initials: HS
authors.lastname: Hsu
authors.forename: P-R
authors.initials: PR
authors.lastname: Hsueh
mesh_terms: D000368:Aged; D016470:Bacteremia / Q000175:diagnosis* / Q000382:microbiology / Q000401:mortality / Q000503:physiopathology; D001431:Bacteriological Techniques; D001769:Blood / Q000382:microbiology; D015331:Cohort Studies; D003470:Culture Media; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007710:Klebsiella Infections / Q000175:diagnosis / Q000382:microbiology / Q000401:mortality / Q000503:physiopathology; D007711:Klebsiella pneumoniae / Q000145:classification / Q000302:isolation & purification*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D013624:Taiwan; D013997:Time Factors
chemical_list: D003470:Culture Media