Bacterial contamination of solutions for parenteral administration for single- and multiple-dose vials after multiple use in the hospital

Outbreaks traced to bacterial contamination of multiple-dose vials are reported in the literature. During a four-month period, multi-dose vials (MDVs), single-dose vials (SDVs), and vials containing self-prepared admixtures were collected from various wards to analyse sterility of their contents. We examined 68 commercially available MDVs containing sodium chloride 0.9% or heparin with added preservative and 17 single dose vials (SDVs) containing aqua ad injectionem or sodium chloride 0.9% and 11 vials with admixtures (ADX) of heparin and sodium chloride 0.9%, both without preservative. Four of 96 (4.17%) vials were not sterile: two of them were contaminated with spore-forming bacteria, two with coagulase negative Staphylococci. Three of the samples were MDVs containing a preservative. The date of the first use was not marked on 28% of the vials. Twenty-eight samples were multiply used, although they were SDVs or ADXs without preservative or without an adequate amount of preservative, respectively. In 15 of 68 MDVs, the time limit after the first use was exceeded. On average, the volume of the samples was 80% of the original volume. A proportion of 4% of vials was not sterile. A training programme for health care workers in aseptic techniques and for validation of the preparation of solutions for parenteral use should be installed.