Nosocomial infections and fever of unknown origin in pediatric hematology/oncology unit: a retrospective annual study

ABSTRACT

Pediatric hematology / oncology patients are faced with an increased risk of nosocomial infections [NIs] that vary in different populations and different institutes with considerable morbidity and mortality. Our aims were to assess the frequency and patterns of NIs in this group of patients relation to the risk of neutropenia and to determine the prevalence of causative organisms and their antimicrobial sensitivities. A retrospective analysis of the data for all children admitted to pediatric hematoloy/oncology unit of Mansoura University, Egypt, was done over one year from January, 2007 to January, 2008. A total of 1564 patients were included [173 children with leukemia, 39 with lymphoma, 49 with other solid tumors, 1293 with thalassemia and 10 withaplastic anemia] corresponding to 2084 admissions and 27092 inpatient days. The Centers for Disease Control and Prevention criteria were used as standard definition for NI. The overall incidence density rates of NIs in all patients and neutropenic patients were 8.6 and 25.3 per 1000 patient-days respectively. The most frequent sites of microbiologically and or clinically documented NIs were blood stream [42.7%], respiratory [25.3%], Urinary [22.2%] and CNS infections [9.8%] whereas nosocomial fever of unknown origin [nFUO] constituted 52.9% of defined cases with incidence density rates of 9.7 and 15.4 per 1000 patient-days in, all patients and neutropenic patients respectively. The frequency of NIs and nFUO were significantly higher during neutropenic days [p<0.001]. Gram-positive organisms represented 64.5% of isolated pathogens [Staphylococci 71.5%, Streptococci 16%, Pneamococci 7% and Enterococci 5.5%], gram-negative organisms represented 30% [E coli 48.6%, Klebsiella 15.7%, and Pseudomonas 35.7%], and Candida 5.5%. Positive cultures were more frequent in summer months [July to September]. The antimicrobial susceptibilities of the isolated organisms were relatively low [cefoperazone/sulbactam 49.9%, amikacin 35.9%, imipenem/cilastatin 34.4%, cefoperazone 33.6% and vancomycin 36.5%]. Blood stream infection and fever of unknown origin are the most common nosocomial infections in pediatric hematology / oncology patients with a higher risk during neutropenic days. Isolated organisms are multi-drug resistant, predominantly gram-positive pathogens