The impact of the central venous catheter on the diagnosis of infectious endocarditis using Duke criteria in children with Staphylococcus aureus bacteremia.

Background: Infective endocarditis (IE) is a known complication of Staphylococcus aureus bacteremia in pediatric patients. We sought to evaluate the impact of prolonged bacteremia associated with a retained central venous catheter (CVC) in the diagnosis of IE using Duke criteria.

Methods: We conducted a 13-year retrospective review of hospitalized patients with blood cultures positive for S. aureus from 1993 to 2005. Subjects were identified from the microbiology database and medical records. To identify patients with IE we retrospectively applied the Duke criteria by recording the number of positive blood cultures, time to sterilization, presence of congenital heart disease, fever >38.5 degrees C, and echocardiographic findings.

Results: During the study period, 344 events of S. aureus bacteremia were identified in 316 pediatric patients. S. aureus bacteremia attributable mortality was 1.7% (n = 6), all among patients with comorbid conditions. By applying the Duke criteria to the 206 (60%) patients who received echocardiographic evaluation, 78 (37.9%) patients were given a diagnosis of IE (7 definite; 71 possible). The incidence of definite IE in patients with CVC is 3.4% and the incidence in patients without CVC is 3.4% (P = 0.6305). The incidence of possible IE in patients with CVC is 42.9%, whereas the incidence in patients without CVC is 23% (P = 0.002).

Conclusions: Evaluation for IE is inconsistently done. The presence of a CVC may skew the diagnosis of IE by prolonging the bacteremic state. We believe that a major microbiologic criteria should not be assumed unless cultures remain positive after removal of CVC.