Value of Rapid Nitrite Screening Test with or without Leukocyte Esterase Test in Detection of Asymptomatic Bacteriuria in Thai Pregnant Women

Abstract

Objective: To determinethe sensitivity, specificity, positive predictive value, and negative predictive value of the rapid dipstick test for detection of asymptomatic bacteriuria (ASB) in pregnancy, and to investigate contributing factors that could relate to having ASB in obstetric patients.

Materials and Methods: Clean-catch midstream urine samples were collected from 414 pregnant women for bacterial culture and rapid screening tests : the nitrite and leukocyte esterase(LE) dipsticks.   

Rrsults: Thisstudy showed the sensitivity of the nitrite test being 29%, the LE test being 47%.Wheneither the nitrite or LE test being positive, the sensitivity increased tobe64%.Both the nitrite and LE test had high specificity of 99.2% and 92.4%, respectively, and high negative predictive value of 97.0% and 97.6%, respectively. We did not find any significant differences in contributing factors between patients that had a positive urine culture and those that had a negative urine culture.

Conclusion: A combination of nitrite and LE testing improved sensitivity for the detection of asymptomatic bacteriuria (ASB), but may not be suitable for screening of ASB. However, the combination of nitrite and LE testing would be useful in monitoring patients after antibiotic treatment for ASB due to the high specificity and high negative predictive value of the combined tests.