Excess centrifugation may destroy cellular and formed elements. Studies have shown that there are many false positive results with dip stick urinalysis on urines obtained from children under the age of 2 and pregnant women. Therefore, microscopic urinalysis is preferred to the dipstick method in these populations. A positive nitrite reaction on fresh urine implies bacterial action and the esterase reaction implies the significant presence of granulocytes. Microscopic examination of the urinary sediment is appropriate where the dip stick reaction for protein or blood is positive.
Studies show the dip stick esterase is a reliable indicator of pyuria.
A dip stick testing positive for blood requires microscopic examination to delineate between hematuria and hemoglobinuria and for detection of casts. Protein requires a search for casts. Clean catch urine obtained after penile or perineal cleansing using a face cloth and soap is satisfactory without the use of disinfectants.1 The urine obtained in this manner in the symptomatic individual with 108 colony forming units per mL is diagnostic of infection4. Multiple organisms on culture may be encountered in the elderly, the immune suppressed and those with catheters. If infection is present, treatment should follow and monthly urine cultures should follow until delivery.