Preventing Staphylococcus aureus bacteremia and sepsis in patients with Staphylococcus aureus colonization of intravascular catheters: a retrospective multicenter study and meta-analysis

Two previous studies in tertiary care hospitals identified Staphylococcus aureus colonization of intravascular (IV) catheters as a strong predictor of subsequent S. aureus bacteremia (SAB), even in the absence of clinical signs of systemic infection. Bacteremia was effectively prevented by timely antibiotic therapy. We conducted this study to corroborate the validity of these findings in non-university hospitals.Using the laboratory information management systems of the clinical microbiology departments in 6 Dutch hospitals, we identified patients who had IV catheters from which S. aureus was cultured between January 1, 2003, and December 31, 2008. Patients with demonstrated SAB between 7 days before catheter removal and 24 hours after catheter removal were excluded. We extracted clinical and demographic patient data from the patients' medical records. The primary risk factor was initiation of anti-staphylococcal antibiotic therapy within 24 hours, and the primary endpoint was SAB >24 hours after IV catheter removal. Subsequently, we performed a systematic review and meta-analysis of all observational studies evaluating the effect of antibiotic therapy for S. aureus IV catheter tip colonization.In the current study, 18 of the 192 included patients developed subsequent SAB, which was associated with not receiving antibiotic therapy within 24 hours (odds ratio [OR], 4.2; 95% confidence interval [CI], 1.1-15.6) and with documented exit-site infection (OR, 3.3; 95% CI, 1.2-9.3). When we combined these results with results of a previous study in a university hospital, a third risk factor was also associated with subsequent SAB, namely corticosteroid therapy (OR, 2.9; 95% CI, 1.3-6.3). We identified 3 other studies, in addition to the present study, in a systematic review. In the meta-analysis of these studies, antibiotic therapy yielded an absolute risk reduction of 13.6% for subsequent SAB. The number needed to treat to prevent 1 episode of SAB was 7.4.We conclude that early initiation of antibiotic therapy for IV catheters colonized with S. aureus prevents subsequent SAB.