新生儿重症监护室细菌定植和医院感染的监测

Surveillance of Bacterial Colonization and Nosocomial Infections in Neonatal Intensive Care Unit

目的观察NICU细菌定植及医院感染情况,以降低NICU医院感染发病率。方法 2009年1-12月在本院NICU住院的465例新生儿入院时行痰培养,进行定植菌检测。机械通气患儿更换或拔除气管插管时,常规留气管插管头行细菌培养。所有培养阳性结果行药敏试验。住院时间>48 h的426例新生儿纳入医院感染调查,疑似医院感染时,根据临床表现行相关病原学检查。计算医院感染发病率、日医院感染发病率、呼吸机相关性肺炎(VAP)发病率。结果 465例新生儿行痰培养,72.7%(338/465例)有细菌定植,其中38.8%为正常菌群,61.2%为致病菌。定植的致病菌主要为大肠埃希菌、肺炎克雷伯菌、金黄色葡萄球菌。医院感染发病率为12.4%(53/426例),日医院感染发病率为12.1‰,呼吸机使用率为2.5%,VAP发病率为65.6‰。不同出生体质量组新生儿医院感染发病率差异有统计学意义(2χ=12.35,P<0.05),出生体质量≤1 500 g的新生儿医院感染发病率最高。有致病菌定植的新生儿医院感染发病率高于无致病菌定植的新生儿,差异有统计学意义(2χ=19.88,P<0.05)。结论细菌(尤其是致病菌)定植在NICU很常见,革兰阴性细菌是常见定植致病菌,致病菌定植与医院感染密切相关。对NICU住院患儿进行定植菌检测,有助于减少医院感染的发生。

Objective To investigate the prevalence of bacterial colonization and the incidence of nosocomial infections（NI） in neonatal intensive care unit（NICU）,and find corresponding measures to reduce NI rate.Methods The specimens of the sputum from 465 hospitalized newborn infants during Jan.to Dec.2009 were collected for culture.When the intubation of the newborn infants with mechanical ventilation were replaced or removed,bacterial cultures for the intubation were performed generally.Antibiotic susceptibility tests were performed after bacteria had been identified.Four hundred and twenty-six newborn infants who were admitted in the NICU for more than 48 h were enrolled to investigate the incidence of NI.When the newborn infants were suspected of NI,they had been inspected for relevant etiology according to clinical manifestations.The incidence of NI and ventilator-associated pneumonia（VAP） of the newborn infants were calculated.Results Three hundred and thirty-eight bacterial strains were separated from 465 newborn infants,the rate of bacterial colonization was 72.7%.Of those strains,38.8% were normal strains,61.2% were pathogenic strains.The major colonized pathogenic strains in NICU were escherichia coli,klebsiella pneumonia and staphylococcus aureus.The rate of NI was 12.4%（53/426 cases）in the NICU.The incidence of NI per 1 000 infants-days was 12.1.Mechanical ventilation was applied in 2.5% newborn infants.The rate of VAP was 65.6 per 1 000 ventilator-days.Significant differences of the incidence rate of NI were observed between birth-weight groups（χ2=12.35,P0.05）.The incidence rate of NI in very-low-birth-weight neonates group were the highest among all different birth-weight groups.The incidence rate of NI in pathogen colonization group were also higher than that in non-pathogenic bacteria colonization group（χ2=19.88,P0.05）.Conclusions The colonized bacteria especially pathogenic strains in NICU are common.Gram-negative bacillus is the main pathogen isolated from newborn infants in NICU.Pathogenic bacteria colonization has close connection with NI.Monitoring bacterial colonization is helpful to control NI in NICU.