Why would someone need a leukocyte esterase urine dipstick test?

Urinary infection: Leukocyte esterase is a surrogate marker for the presence of white blood cells in the urine and usually indicates urinary infection.

? of WBCs in urine: Simple, rapid surrogate test for presence of white blood cells in urine. Combined with nitrite test (both present on a urine dipstick) used to diagnose urinary infections when 1 or both +ve. Can provide false +ve in presence of vaginal eithelial cells which are common in "clean" voided specimens from women. Can be confirmed by microscopy of spun urine specimen or urine culture.