Molecular-based diagnosis of bacteremia in the setting of fever with or without neutropenia in pediatric hematology-oncology patients

BACKGROUND:: Prompt evaluation and appropriate treatment with wide-spectrum antibiotics is considered mandatory for febrile oncology patients especially during neutropenia. Central venous catheters are widely used in pediatric oncology patients and are often the source of infections. Patients are usually admitted for follow-up and administration of antibiotics. Aims were to assess the efficacy of the polymerase chain reaction (PCR) method in identifying bacteria in blood samples as compared with standard blood cultures. METHODS:: This was a prospective study, which included all patients with central venous catheters admitted to the pediatric hematology-oncology department over the 14-month period. Demographic, clinical, and laboratory variables were compared in bacteremic and nonbacteremic patients. Standard microbiological cultures were compared using the PCR technique. RESULTS:: From September 2004 to November 2005, 148 blood cultures (70 patients) were evaluated. Positive blood cultures were detected on 21 (18.3%) occasions. PCR had sensitivity of 46%, specificity of 98%, positive predictive value 86%, and negative predictive value 89%. The PCR identified fastidious bacteria in 2 occasions when standard cultures were negative. CONCLUSIONS:: Inspite of low sensitivity, PCR may help with early identification of bacteremia. Improving this technology is warranted.