Objective: To investigate the incidence of nosocomial infections of newborn infants in neonates and to explore the risk factors and strategies of infection control.
Methods: There were 433 confirmed cases of nosocomial infection in the neonatal ward of the authors' hospital from January 2007 to December 2009. Their data of epidemiological and clinical characteristics, results of etiological examinations and antibiotic resistance were retrospectively analyzed.
Results: During the study, the number of hospitalizations were 6437. Nosocomial infection occurred in 433 patients 513 times. The overall nosocomial infection rate was 6.82%. The overall hospitalization days were 73 663 and nosocomial infection patient-day rates were 6.96‰. The VAP infection rate was 28.7‰. The CRBSI rate was 3.5‰. Gestational age (OR = 1.049), mechanical ventilation (OR = 1.810), umbilical vein catheter (OR = 1.106), hospitalization days (OR = 1.081), premature rupture of membrane (OR = 1.433) were the risk factors for the development of nosocomial infection. There were 197 (38.4%) cases of pneumonia, which was the most common nosocomial infection in Neonatal Ward. There were 129 cases of ventilator-associated pneumonia (VAP), which accounts for 65.5% of pneumonia and 24.4% of cases treated with ventilator. The next was sepsis, 124 cases (24.2%) and 64 cases of diarrheal disease (12.7%). One hundred and eighty two (54.4%) strains of isolates were Gram-negative bacteria, which accounted for the highest proportion. The predominant pathogens of Gram-negative bacteria were Klebsiella pneumoniae (19.6%), followed by Acinetobacter baumannii (8.1%), Pseudomonas aeruginosa (7.2%), Stenotrophomonas maltophilia (4.8%) and Escherichia coli (4.8%). The isolation rates of Klebsiella pneumoniae and Escherichia coli with positive extended-spectrum beta-lactamases (ESBLs) were 91.4% and 75%, respectively. Those two bacteria were universally resistant to cephalosporins. The rate of resistance to imipenem of Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa were 1.5%, 11.1% and 41.7%. The isolation rates of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus were 28.6% and 95.5%.
Conclusion: It is important to identify the high risk factors for nosocomial infections in newborn infants. To shorten time for mechanical ventilation and hospitalization days, removal of the central venous catheter as early as possible would be conducive to reducing the morbidity of nosocomial infection. The main pathogens were Gram-negative bacteria. The multidrug resistance of Enterobacteriaceae and Non-fermenters is serious.