Serious bacterial infections in febrile outpatient pediatric kidney transplant recipients

Background: The purpose of this study was to describe the incidence of serious bacterial infections in febrile outpatient pediatric kidney transplant recipients and to assess the utility of using white blood cell indices to identify patients at low risk for bacteremia. Methods: A retrospective study was conducted on all kidney transplant recipients followed at a single children's hospital. All outpatient visits from January 1, 1995 to June 6, 2007 in which fever was evaluated were reviewed. Patients with history of a primary immunodeficiency, receiving concurrent chemotherapy, or a stem cell or small bowel transplant were excluded. Demographic, historical, physical examination, laboratory, and radiographic data were then recorded. Results: In all, 101 patients had 251 individual episodes of fever evaluation. In 209 visits, a blood culture was drawn with results available. There were 21 (10.0%) true positive blood cultures and 3 (1.4%) false positives. Two-thirds of the true positive blood cultures occurred in patients with indwelling hardware. There was a positive urine culture in 52/192 (27.1%) visits. Pneumonia was diagnosed in 14/74 (18.9%) visits. In nonill-appearing children without indwelling central lines or focal bacterial infections, the incidence of bacteremia was zero. No practical decision rule based on white blood cell indices could be derived. Conclusions: The majority of bacteremic cases in febrile outpatient pediatric kidney transplant patients occurred in patients with indwelling hardware. We did not detect any occult cases of bacteremia in this study cohort. A larger prospective multicenter study is required to confirm the low incidence of bacteremia in this patient subset.