Diagnostic accuracy of leucocyte esterase and nitrite in the rapid urine dipstick test in detecting asymptomatic bacteriuria among pregnant women in a low resource setting

Abstract

Background: There is a need to evaluate simple, cheap, affordable, but reliable forms of alternative investigations for quick diagnosis of asymptomatic bacteriuria among pregnant women. Objective: To determine the accuracy of leucocyte esterase and nitrite in a rapid urine test in comparison with urine culture in the detection of asymptomatic bacteriuria among pregnant women in a low-resource setting. Materials and Methods: This was a cross-sectional comparative study of 235 consenting pregnant women at Alex Ekwueme Federal University Teaching Hospital in Abakaliki, Ebonyi State, Nigeria over a period of 6 months. Clean-catch mid-stream urine specimens of participants with no clinical features of urinary tract infection were collected and tested for nitrite and leucocyte esterase, laboratory microscopy, culture, and sensitivity. The validity of the dipstick test was compared with urine culture as the gold standard. A P value ≤ 0.05 was considered statistically significant. Results: About 72 (30.6%) of the participants were culture-positive, while 43 (18.3%) were positive for dipstick (either separately or in combination). Urine dipsticks that were both positive for leucocyte esterase and nitrite, when combined, demonstrated a sensitivity of 51.3% and a specificity of 96.3%, with a positive predictive value of 86.1%, a negative predictive value of 81.8%, and an accuracy of 82.6% in comparison with urine culture. Conclusion: Detection of leucocyte esterase and nitrite in urine using a dipstick test revealed moderate sensitivity, high specificity, and accuracy values. Therefore, this can be used for the detection of asymptomatic bacteriuria in a low-resource setting where facilities for culture are not readily available.

Keywords

• asymptomatic bacteriuria
• low-resource environment
• pregnancy
• urinary tract infection