|摘要||目的 研究北京大学第三医院近年来血流感染的微生物学和流行病学特征.方法 回顾性分析2005年1月1日至2007年12月31日的全部血液培养检查中培养阳性的患者的临床资料和微生物学资料.成组设计资料构成比的差异比较采用X2检验.结果 3年中共对3 795例患者和5 138个病程进行了血液普通细菌培养,标本共6 488套.按有氧瓶统计,阳性率为9.9%.住院患者3年平均血流感染发生率为40.8/1万.共检出导致感染的菌株593株,其中医院内获得感染病原483株,占81.5%.全部菌株和院内感染菌株构成比:革兰阳性菌分别占38.5%和42.0%,革兰阴性菌分别占54.7%和49.9%,真菌(全部是假丝酵母菌)分别占6.8%和8.1%.全部菌株中,大肠埃希菌占25.3%,血浆凝固酶阴性葡萄球菌占18.8%,金黄色葡萄球菌和肺炎克雷伯菌分别占7.1%和7.4%,肠球菌属占8.3%,铜绿假单胞菌和鲍曼不动杆菌分别占3.2%和2.2%,厌氧菌占0.7%.复数菌感染共10例,占全部感染的1.7%.院内感染中链球菌(X2=9.240,P=0.002)和大肠埃希菌(X2=23.609,P<0.01)明显多见于非ICU病房,而假丝酵母菌则明显多见于ICU病房(X2=5.498,P=0.019).入院至标本留取时间差为15.1(大肠埃希菌)～29.7 d(鲍曼不动杆菌).3年中主要菌株的耐药性无明显变化.结论 北京大学第三医院住院患者血流感染发生率为40.8/1万.致病菌株以革兰阴性菌为主.
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.|