The Accuracy of Rapid Urine Tests in Detecting Asymptomatic Bacteriuria in Pregnancy at University of Maiduguri Teaching Hospital, Maiduguri, Nigeria

Abstract

Background: Asymptomatic bacteriuria (ASB) is the most prevalent Urinary tract infection (UTI). The gold standard for detecting ASB is urine culture, which requires trained personnel who are not always readily available in some parts of the world. Quick office-based tests such as urine microscopy and reagent strip testing are also used as screening tests at points of care, reserving culture for positive and symptomatic cases. Objectives: This study determined the risk factors for ASB and the accuracy of reagent strip testing and microscopy in detecting ASB among pregnant women. Methods: A cross-sectional study of 150 women attending the antenatal clinic of the University of Maiduguri Teaching Hospital (UMTH) in Maiduguri, Nigeria, was conducted from 3rd October to 13th December 2010. Demographic and clinical variables were obtained. Midstream urine specimens were collected from each patient and used for reagent strip testing, microscopy, culture and antibiotic susceptibility testing. The performance of the various tests alone and in combination was evaluated using urine culture as the standard. Results: Sickle cell trait, history of UTI before index pregnancy and anaemia at booking were significant risk factors for the development of ASB. A combination of positive leucocyte esterase and nitrite tests had specificity and a positive predictive value of 100% each. Similarly, the combination of pus cell count and gram stain, termed enhanced urinalysis had specificity and positive predictive values of 99.1% and 95.0%, respectively. Conclusion: Sickle cell trait, UTI before index pregnancy and anaemia at booking are significant risk factors for ASB. A combination of negative dipstick leucocyte esterase, nitrite, and negative enhanced urinalysis effectively rules out ASB. Urine culture can be restricted to positive and symptomatic patients.