Analysis of very low birth weight infants with nosocomial infection within eleven years

Abstract

Objective To investigate the epidemiological and clinical characteristics, risk factors, outcome and prevention strategy of very low birth weight infant （VLBWI） with nosocomial infection in neonatal intensive care unit （NICU）. Methods The VLBWIs whose birth weight were less than 1500 g and hospital stays were more than 48 hours in NICU of Peking University Third Hospital from January 1, 1998 to December 31, 2008 were selected in this study. They were divided into nosocomial infection group and non-infection group. The clinical features and outcomes of nosocomial infection were summarized and the risk factors of which were analyzed with Logistic regression. Results There were 158 VLBWIs who fit for the criteria of our study during the eleven years, the mean birth weight was （1263.8± 155.5） g and the mean gestational age was （30.4±2.1） weeks. There were 70 times and 56 cases suffered from nosocomial infections. The incidence of nosocomial infection was 35.4% and hospital stay-related incidence was 14.4‰. Among 70 times of infections, there were 40（57.1%） pneumonia, 22（31.4%） septicemia, 4（5.8%） thrush, 1（1.4%）conjunctivitis, 1 （ 1.4%） upper respiratory tract infection and 2 （2.9%） unknown site infections.Forty-one strains of bacteria were isolated from 121 specimens, among which gram-negative bacillus accounted for 56.1% and gram-positive cocci for 46.3%. The duration of hospital stay of VLBWIs with nosocomial infection was significantly longer than that without [（43.7±15.5） d vs （26.3±14.4） d] （t = -7.058, P〈0.01）. The fatality rate of VLBWIs with and without nosocomial infection was 3.6% （2/56） and 3.9% （4/102）, and there was no significant difference （x2 = 0.012,P〉0.05）. Logistic regression showed that mechanical ventilation （OR = 3.388, 95% CI： 1.656-6.932, P=0.001） and parenteral nutrition （OR= 7.054, 95%CI： 2.005-24.813, P=0.002） were risk factors of nosocomial infection. Conclusions The incidence of nosocomial infection in VLBWIs in NICU is high. Mechanical ventilation and parenteral nutrition should be avoided and the duration of invasive operation and treatment should be shortened as much as possible to minimize the chances of nosocomial infection in VLBWIs. Key words: Infant,very low birth weight Cross infection Risk factors