Asymptomatic bacteriuria in pregnancy: what is the validity of urine sediment microscopy as a screening tool in a low resource setting?

ABSTRACT

Background: Asymptomatic bacteriuria in pregnancy should be screened and treated to reduce the risk of morbidity and mortality. Urine culture is the recommended test. In low resource setting with large patient load urine culture in all pregnant patients is not feasible. In this study authors have assessed the validity of urine microscopy in the screening of asymptomatic bacteriuria in pregnancy.Methods: Midstream clean catch urine specimen collected from 675 pregnant women was subjected to urine sediment microscopy and culture. It was considered screen positive if pus cells were >5/HPF. Asymptomatic bacteriuria was diagnosed if there were >/=100000 CFU of a single uropathogen per ml. Results obtained were statistically analysed for the prevalence of asymptomatic bacteriuria, sociodemographic and medical risk factors, causative organisms, antibiotic sensitivity and validity of urine sediment microscopy in detecting asymptomatic bacteriuria.Results: The incidence of asymptomatic bacteriuria in our study was 10.2%. The incidence was higher in the age group between 20-30 years, in gravida 3 and above, in upper lower and lower socioeconomic status, in women with hyperglycemia in pregnancy and anaemia. E. coli was the commonest bacterial isolate in culture positive cases. Bacterial isolates had poor sensitivity for Ampicillin, amoxicillin and nitrofurantoin and good sensitivity for cephalosporins and aminoglycosides. The sensitivity, specificity, positive and negative predictive values for urine microscopy was 43%, 85%, 25% and 93% respectively.Conclusions: This study shows poor sensitivity and positive predictive value and good specificity and negative predictive value.