Central line-associated bloodstream infection: is the hospital epidemiology of methicillin-resistant Staphylococcus aureus relevant?

We aimed to evaluate the risk factors, including the hospital epidemiology of methicillin-resistant Staphylococcus aureus (MRSA), for central venous line-associated and laboratory-confirmed bloodstream infections (CLA-BSI and LC-BSI, respectively). The risk factors examined included the age and sex of patients, whether or not they were in the surgery service, the number of days of central line (CL) placement, the monthly number of inpatients and those positive for MRSA, and whether the standard or maximal barrier precautions were observed at CL insertion. As the outcome factors, we selected CLA-BSI and LC-BSI, while precluding repeated isolation within 28 days. Of a total of 22,723 device days in 927 patients with CL placement, we observed 81 CLA-BSIs and 40 LC-BSIs, rates of 3.56 and 1.76 (/1000 device-days), respectively. Logistic regression analysis revealed a single significant factor, CL placement of more than 30 days, with odds ratios of 3.038 [95% confidence interval (CI) 1.733-5.326; P < 0.001] for CLA-BSI and 3.227 (95% CI 1.427-7.299; P = 0.005) for LC-BSI. Both BSIs included MRSA in seven events without temporal clusters. We conclude that the factor of long CL placement outweighs other risk factors, including the hospital epidemiology of MRSA.