Usefulness of nitrite test in screening for urinary tract infection in children with sickle cell anaemia

Abstract

Background: Screening for urinary tract infection (UTI) among children with SCA can lead to early detection of UTI in childhood. This may necessitate further evaluation and early effective interventions with reduction in the number of individuals who develop end-stage renal disease (ESRD). Objectives: To evaluate the usefulness of nitrite test in screening for UTI in children with SCA. Methods: Two hundred and seventy two children with SCA both in steady state and in crisis (anaemic and vaso-oclusive), aged 6 months to 15 years were screened for significant bacteriuria. The study was conducted over a period of 8 months (February to September, 2012). Urine samples were aseptically collected and incubated aerobically at 37°C for 24 hours. The study was conducted in the paediatric medical ward, emergency paediatric unit and institute of child health, Banzazzau all of the Department of Paediatrics, Ahmadu Bello University Teaching Hospital, Zaria. Children whose urine samples yielded ≥10⁵cfu/ ml of urine on two consecutive cultures were regarded as having significant bacteriuria. Results: Bacterial isolates were detected in 22 (8.1%) of the 272 subjects with SCA. Of the 272 children with SCA, 66 (24.3) had positive nitrite test. The nitrite test has the sensitivity, specificity and positive and negative predictive values of 68.2%, 79.6% and 22.7% and 96.6% respectively. Conclusion: Nitrite test is not a useful screening tool for the diagnosis of UTI in SCA children.