Abstract

Objective: In this study, we aimed to determine the contamination rates of urine samples sent to the microbiology laboratory in terms of age and gender and investigate the factors that affect these rates.

Methods: 17 730 urine cultures sent to the microbiology laboratory between May 17, 2017 and November 8, 2019 were evaluated retrospectively. The bacteria that grew more than 104 CFU/ml in urine cultures were accepted as uropathogenic. Urogenital flora elements or cultures which resulted with three or more different strains were considered contaminated.

Results: 6008 (33.9%) of the urine cultures were positive, and no growth was observed in 11 722 (66.1%). We evaluated 3647 (20.58%) of them as contamination. The contamination rate was 25.3% in female urine samples and 15.6% in male urine samples, (28.9%) in children less than 1-year-old and close to mean value in children older than 5 years old (19.9%). Mean values of boys aged in 0-5 years were higher than girls.

Conclusions: In our study, the contamination rate between 0-5 years was higher than the others. It was higher in females and children under 5 years of age than other age groups (p<0.05). The contamination rate was highest in males under 5 years old and females older than 5 years old, and the difference was statistically significant (p=0.037 and p=0.000). Contamination may result from improper pre-analytical and post-analytical processes or it also may result from differences in agent identification. The rates can be reduced by using appropriate techniques for urine collection, storage, and transport, which are the main tasks of the pre-analytical phase.  For this reason, the processes and the standards in identifications should be applied correctly.