Microbiology collection device and ISO 15189: an appropriate selection

In light of the emphasis being placed on quality in the clinical laboratory, and given the increased awareness of the importance of the pre-analytical phase of specimen processing, the selection of the most appropriate collection device cannot be overemphasised. While swab systems are considered less optimal than direct plating for culturing purposes, they have become increasingly important in view of the delay of specimen transport necessitated by recent strategies of cost containment and consolidation of laboratory services. If the pre-analytical step is performed with suboptimal quality, even the highest standards of laboratory quality management and/or automation will not compensate for the initial flaws, and this may have a negative effect on the care patient pathway.

Collection and transport of bacterial specimens to the laboratory is a critical component in the success of the diagnostic process. Transport time and temperature are now a major concern as the original concept and design of swab transport devices is 70 years old, and they were developed in a time when the patient was only minutes away from the laboratory. Swabs are a very much used sampling device, and the swab components play a major, but often overlooked, role in sampling. The preservation and viability of organisms must be assured. Transport swabs must be seen as a critical component of the diagnostic pathway. Failure to ensure viability of microorganisms at the pre-analytical stage will have an adverse effect on any relevant clinical information received from the investigation.

Tissue biopsy and fluid aspiration methods are preferred for collection of clinical samples; however, swab transport systems are commonly used due to their low cost and practicality (ease of use) and the ability to maintain viability for aerobic, anaerobic and fastidious microorganisms over extended times.¹