What indicates vaginal or urethral contamination of urine?

The presence of many squamous epithelial cells in a urine sample indicates contamination from the vaginal or urethral area. Squamous epithelial cells are typically linings found in the outer layer of the urethra and surrounding genital areas. When urine is collected, especially in midstream samples, high levels of these cells suggest that the sample has not been collected in a sterile manner, leading to contamination from the epithelial surfaces of the genital area.

In clinical practice, a clean catch urine sample is recommended to minimize contamination and ensure an accurate assessment of urinary health. High levels of squamous epithelial cells can obscure the results of other tests and can signify that the sample may not represent the urine from the bladder, which can lead to misinterpretation of conditions like urinary tract infections or other urinary tract issues.