[Clinical analysis of adult primary bloodstream infection]

Evaluate the microbiological and epidemiological characteristics of primary bloodstream infections as well as the associated patients' clinical features at Peking Union Medical College Hospital.

Microbiological and clinical data of the adult patients with primary bloodstream infections during January 1, 2008 and December 31, 2009 were retrospectively collected and evaluated. Pearson χ(2) test was used to compare the difference between proportions and Logistic regression was used in multivariate analysis.

Five hundred and eighty-six strains of microbes were isolated from 494 adult patients with primary bloodstream infections. There were 80 patients with polymicrobial primary bloodstream infection of the 586 isolates, coagulase-negative staphylococci (175, 29.9%) was the most common, followed by Escherichia coli (93, 15.9%), Enterococcus species (60, 10.2%), Streptococcus species (41, 7.0%), and Staphylococcus Aureus (39, 6.7%). Central-line was the leading suspected infective source among the suspected infective source involving 108 (18.4%) isolates. Excluded the 108 isolates with suspected sources, 77 (45.3%) out of 167 patients with the primary bloodstream infections caused by coagulase-negative staphylococci or Staphylococcus Aureus had a central-line, with a higher proportion of the patients with a central-line than the patients with bloodstream infection caused by other pathogens (χ(2) = 10.419, P = 0.001). One hundred and fourteen patients died during hospitalization, with the crude mortality rate 23.0%. Fifty-nine patients (11.9%) died due to primary bloodstream infection. The patients with polymicrobial bloodstream infection were with a higher attributable mortality (OR = 2.159;95%CI 1.165 - 4.002; χ(2) = 6.194, P = 0.013). In the multivariate analysis, the independent risk factors of crude mortality rate to primary bloodstream infections were elderly patients, central neurological disorder, mechanical ventilation, and reservation a central-line.

The most common microbe causing primary bloodstream infections was G+ cocci. Polymicrobial primary bloodstream infection added risk to attributable in-hospital fatality ratio. Elderly patients, neurological disorder, reservation of central-line, and mechanical ventilation were the independent risk factors of crude in-hospital fatality ratio.