Reagent Strip Testing (RST) For Asymptomatic Bacteriuria (ASB) in Pregnant Women: A Cost-effective Screening Tool in Under-resourced Settings
671-673
Correspondence
Balamurugan S.
3 D KG Traditions
1 North Gopalapuram First Street, Chennai, India - 600086
Phone: 09444443996
E-mail: kayalb75@yahoo.co.in
Context: Bacteriuria in asymptomatic pregnant women, when it is not detected and treated, may lead to a number of maternal and foetal complications. Culture, though it is a gold standard test for the diagnosis of bacteriuria, it is time consuming and expensive and it is not available at all the healthcare settings. A pre-screen with a simple, rapid and less expensive near patient testing by using reagent strips (RST) can minimise the requirement of the culture, especially in antenatal women without urinary symptoms.
Aims: This study evaluated the performance characteristics of Reagent Strip Testing (RST) as compared to bacteriologic culture in detecting bacteriuria.
Settings and Design: A prospective, blinded study.
Methods and Material: Urine samples from 100 consecutive women without urinary symptoms, who attended routine antenatal clinics were subjected to Reagent Strip Testing (RST) (by using four infection associated markers - leukocyte esterase, nitrites, blood and protein) and Bacteriologic Culture.
Statistical Analysis Used: The performance characteristics of Reagent Strip Testing were evaluated against the gold standard urine culture. Different markers singly, or in combination, were assessed to find out the best test strategy for the Reagent Strip Positivity.
Results: The prevalence of ASB in pregnant women, as was determined by culture, was 13%. Reagent Strip Testing (RST) for bacteriuria by using a single marker leucocyte esterase or nitrites yielded a sensitivity of 85% and 62%, which increased to 100%, with a negative predictive value of 1, if the criterion was broadened to positivity with one or more of four infection associated markers. This seemed to be a good rule out test strategy that could reduce the number of urine samples which were sent for culture. Thus, an algorithm of pre-screening the urine samples for infection with reagent strips by using four infection associated markers and performing the culture only on dipstick positive cases could prove to be cost effective in averting the complications which were associated with ASB.
Conclusions: Urinary dipstick testing in a near patient setting is a valuable resource to screen out the negative urine specimens at the point of care. If properly implemented, this programme can result in an improved use of the laboratory resources and it can aid the clinicians in instant clinical decision making.