Chelsea Leung¹, Jazarah-Jay Goldfinch¹, Harsha Samarasekara^2
1Microbiology laboratory, NSW Health Pathology, Nepean Hospital, Penrith, NSW.

The recently revised ISO15189/2022 and CLSI guidelines for quality indicators (QI) for process improvement and monitoring (GP35A) have highlighted the adoption of QIs to optimise pre-analytic process. Urine is one of the most frequent samples received in a clinical microbiology laboratory. Contaminated urine cultures due to sub optimal collection and transport can potentially delays directed antibiotic therapy. The impact is much more in regional and rural laboratories where transport travel for longer time.

To identify pre-analytic factors leading to urine culture contamination in cultures processed at Nepean and Orange Microbiology laboratories.

A retrospective analysis was conducted with the data of urine cultures received in Nepean Hospital and Orange Hospital over a 12-month period between 2023 and 2024. Site-specific urine culture contamination (mixed growth) rate was calculated.

Urine culture contamination rates for Nepean and Orange laboratories were 2.58% and 24.18% respectively. 

Active interventions are needed to reduce urine contamination rate. Appropriate urine containers Staff and patient education on proper sample collection techniques, sample transportation guidelines should be reviewed and reinforced. Samples from rural hospitals travelling longer to reach the main laboratory outside recommended temperatures would have been contributed.

Original research idea was from Dr Samarasekara. The laboratory work was performed by Nepean and Orange Microbiology staff. All participants contributed to the write up.