Microbiological analysis of bloodstream infections in Peking University Third Hospital from 2005 to 2007 / 中华传染病杂志

ABSTRACT

Objective To investigate the microbiological and epidemiological characteristics of bloodstream infections in Peking University Third Hospital Methods The clinical, microbiological and epidemiological data of bloodstream infections in Peking University Third Hospital from January lst,2005 to December 31st, 2007 were analyzed retrospectively. Differences in proportions were compared using X2 test. Results Six thousand four hundred and eighty-eight blood culture tests for 5 138 episode of bloodstream infections of 3 795 patients were performed. The positive rate was 9.9%. The average incidence rate of nosocomial infection was 40.8 cases per 10 000 hospital admissions. In the 593 pathogens, 483 (81.5%) were pathogens causing nosocomial. The ratio of Gram-positive microbs, Gram-negative ones and fungi (all were Candida spp.) were 38.5%, 54.7%, and 6.8%, respectively. The corresponding ratio of nosocomial pathogens were 42.0%, 49.9% and 8.1%, respectively. The most frequently isolated strain was Escherichia coli (25.3 %). The coagulase negative staphylococcus was the second one (18.8%). The corresponding ratio of Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus spp. , Pseudornonas aeruginosa , Acinetobacter baumannii and anaerobs were 7.1%, 7.4%, 8.3%, 3.2%, 2.2% and 0.7%, respectively. Ten patients (1.7%) had experienced polymicrobial infection. In hospital setting, Streptococcus spp. And Escherichia coli infections were more frequently in non-intensive care unit (ICU) than ICU (X2= 9.240, P= 0.002; X2= 23.609, P,<0.01; respectively). But the infection rate of Candida spp. Was significantly higher in the ICU (X2= 5.498, P= 0.019). The time interval between hospital admission and onset of infection for the most frequently isolated pathogens ranged from 15.1 days (Escherichia coli) to 29.7 days (Acinetobacter baumannii). The degree of resistance to the common antimicrobal agents had no change in the three years. Conclusions The average incidence rate of nosocomial bloodstream infection is 40.8 cases per 10 000 hospital admissions. The main pathogens are the Gram-negative microbs.