Patterns of microbial growth in urine cultures in a pediatric hematology/oncology unit over a one-year period: a single institution study

BACKGROUND: Urinary tract infections (UTIs) may present with nonspecific symptoms and without any definitive clinical signs other than fever, hence may be missed without a routine urine analysis. We retrospectively evaluated all cases of culture-positive urine infections in pediatric oncology patients in our center during the year 2015. METHODS: We assessed all positive urine culture incidents for pediatric patients receiving treatment and/or follow-up at our center during 2015. Analysis was performed on patients with regards to clinical, microbiology and pertinent lab findings as well as associated risk factors. RESULTS: There were 151 episodes of documented positive urine cultures among 73 patients. Majority of positive urine cultures were found in solid tumor patients (41%), followed by hematological malignancies (26%). Most organisms detected were gram-negative organisms (84%), with E.coli being the most frequent (51%). Forty percent of bacteria were resistant to standard broad-spectrum antibiotics, with the majority being extended-spectrum beta-lactamase-producing. Most of these infections occurred in patients receiving prophylactic antibiotics (46 out of 50). Approximately two thirds of patients were not febrile on the day of culture (64%) and almost half of the reported episodes were associated with urinary symptoms. Pyuria, leukocyte esterase and nitrites were positive in 39%, 51% and 19% of samples, respectively. CONCLUSIONS: Positive urine culture in children with cancer may not be associated with urinalysis abnormalities, particularly in patients with neutropenia. When selecting empiric treatment for cancer patients with UTIs, one should take into consideration the institutional patterns for resistance and use of prophylactic antibiotics.