Diagnosis of venous access port colonization requires cultures from multiple sites: should guidelines be amended?

Data on microbiological management of withdrawn venous access ports (VAPs) are scarce. The aim of our study was to assess the validity of Gram stain and culture performed on VAPs to detect colonization and VAP-related bloodstream infection (VAP-RBSI). We prospectively performed cultures of the following: catheter tip (roll-plate and sonication), port content aspirate before and after sonication, port sonication fluid (PSF), and port internal surface biofilm (ISB). The gold standard of VAP colonization was positivity of at least 1 of the cultures mentioned above. We collected 223 VAPs in which no single culture had validity values reliable enough to predict colonization and VAP-RBSI. The best validity values were those obtained when cultures of catheter tip (roll-plate), PSF, and port ISB were combined. Cultures from several areas on the VAP are necessary to ensure suitable assessment of colonization and VAP-RBSI.