Epidemiological changes in invasive fungal infection in a neonatal intensive care unit

Abstract

Objective To identify the epidemiological changes in invasive fungal infection (IFI) in a neonatal intensive care unit (NICU) to provide information for prevention and treatment of IFI. Methods A total of 102 cases who were diagnosed with IFI among 42 187 neonates hospitalized in the NICU of Affiliated BaYi Children's Hospital, Chinese People's Liberation Army General Hospital from January 1, 2009 to December 31, 2014 were enrolled in this study. Since January 1, 2012, the divisions of our NICU were more specific and intravenous fluconazole was administered as a routine preventive measure for high-risk infants. Clinical information of the IFI cases including general features, incidence, distribution of pathogens and drug (Amphotericin B, Fluconazole, Flucytosin, Itraconazole and Voriconazole) sensitivity were analyzed between former period (January 1, 2009 to December 31, 2011) and latter period (January 1, 2012 to December 31, 2014) by Chi-square test. Results The total incidence of IFI was 2.42‰ (102/42 187), and among the 102 IFI cases, 73.5% (75/102) were preterm infants and 75.5% (77/102) were low birth weight infants. The incidence of IFI in the latter period was lower than that in the former period [1.8‰ (48/26 046) vs 3.3‰ (54/16 141), χ2=9.329, P<0.01]. The incidences of IFI in neonates with gestation age <28, ≥28-<32 and ≥32-<37 weeks in latter period were decreased as compared with those in former period [10.6‰ (3/284) vs 76.9‰ (9/117), χ2=12.569; 6.1‰ (13/2 134) vs 21.9‰ (28/1 277), χ2=16.868; 1.4‰ (12/8 706) vs 1.9‰ (10/5 256), χ2=7.165] (all P<0.01). Altogether 103 pathogen strains were identified from 102 IFI cases as one Candida parapsilosis strain and one Laurent cryptococcus strain were both isolated from one patient. The most prevalent three pathogens were Candida albicans [51.5% (53/103)], Candida parapsilosis [24.3% (25/103)] and Candida glabrata [8.7% (9/103)]. The isolated rates of Candida albicans and Candida glabrata strains in the latter period were higher than those in the former period [63.3% (31/49) vs 40.7% (22/54), χ2=5.218; 18.4% (9/49) vs 0.0% (0/54), χ2=10.868], while the isolated rate of Candida parapsilosis strain was lower in the latter period than that in the former period [12.2% (6/49) vs 35.2%(19/54), χ2=7.355] (all P<0.05). All pathogen strains were sensitive strains except one Candida krusei strain which was isolated in the former period and was resistant to Fluconazole. Conclusions Premature infants born at lower gestational ages or with low birth weights are still at high-risk of IFI, but the incidence of IFI has declined in recent years. Routine administration of fluconazole in high-risk infants in NICU could prevente IFI without increasing drug resistance. Candida albicans is the predominant pathogen of IFI. Key words: Mycoses; Intensive care units, neonatal; Incidence; Infant, low birth weight; Candida