A New Screening Approach For Fast And Accurate Prediction Of Positive And Negative Urine Cultures By SediMAX Compared With The Standard Urine Culture

Abstract

Urinary tract infections (UTI) are the most frequent bacterial infections, and the detection of infection in urine samples is expensive and time-consuming. Also, in laboratories a significant proportion of samples processed yield negative results. For this, screening methods represent an important improvement towards the final UTI diagnosis. SediMAX is an automated microscopy, easier to use in laboratories due to its basic procedure and it is widely used for urine sediment analysis. In our study, we evaluated the performance of SediMAX, applying some screening parameters, compared with the gold standard methods, urine culture, to identify all the positive cases for UTI. We analysed 1185 urine samples from our daily laboratory routine. The basis of our screening model was to establish a cut-off for bacterial count (BACT), as 300 bacteria/µL in order to avoid missing positive cases. However, the sensitivity and the specificity achieved were not enough to identify all UTI infection in urine samples. So, in addition to BACT we have considered other parameters, such as White Blood Cell (WBC), Red Blood Cell (RBC), Yeasts (YEST), Age and Nitrates (NIT). The second screening method reached a sensitivity of 100%, that could be reliably employed in detect of UTIs.