Laboratory Evaluation of Urinalysis Parameters to Predict Urinary Tract Infection

We evaluated the performance of urinalysis dipsticks and microscopic urine sediment analysis as predictors of urinary tract infection (UTI) in patient visiting hospital. The samples were processed for macroscopic examination to observe Leukocyte esterase (LE) and Nitrite (NIT) by dipstick method, microscopic examination to observe pus cells, culture of urine sample on Blood agar and MacConkey agar to identify the potential pathogen and Colony count was evaluated. The positive predictive values was significantly greater for the NIT test alone than for either LE alone and LE and NIT in combination: 68.00% at ≥105 CFU/ml. The LE and NIT combination had a significantly higher predictive value of a negative test then either test alone at all two level of bacteriuria. Microscopic examination for White blood cells (WBCs) and bacteria, found that of the 178 cases were positive for LE, NIT or both by the dipstick method, Among them 115 cases were positive for pyuria, 45 cases were positive for bacteriuria and the rest (28 cases) negative for pyuria or bacteriuria. We concluded that though it is laborious, microscopic urinalysis is a good analytical tool. Taken together with dipsticks, we obtained a clinically-acceptable prediction of urinary-tract infection.