High levels of leukocyte neutrophil esterase are often indicative of a bacterial infection in the specimen being tested and can be diagnostic. Leukocyte neutrophil esterase is a specific enzyme contained in neutrophils, and a high level of this enzyme indicates an increase in the number of neutrophils in the specimen, which may indicate a localized bacterial infection. Leukocyte neutrophil esterase is commonly used in vaginal secretions, urine examination, if the urine leukocyte esterase is positive, combined with the typical clinical manifestations, such as urinary frequency, urgency, dysuria, fever and so on may suggest urinary tract infection. If leukocyte esterase is positive in vaginal secretions, accompanied by symptoms such as vulvar itching and increased secretions, it may suggest bacterial vaginitis. Abnormal test results should be treated promptly by a doctor.