Evaluation of the Diagnostic Performance of urine dipstick test for Detection of urinary tract infections in patients treated in Kenyan hospitals.

Abstract

Introduction Culture is the gold-standard diagnosis for Urinary Tract Infections (UTIs). However, most hospitals in poor-resource countries lack adequately equipped laboratories and relevant expertise to perform culture and therefore heavily rely on dipstick tests as an alternative diagnostic method for UTIs. Research gap In many Kenyan hospitals, routine evaluations are rarely done to assess the reliability of popular screening tests such as the dipstick test. As such, there is a high risk of misdiagnosis emanating from inappropriate or insufficient use of proxy screening tests over the goal standards. As a result, this may lead to misuse, under-use, or over-use of antimicrobials and treatment failure. Aim The present study sought to assess the reliability of the urine dipstick test as a proxy for the diagnosis of urinary tract infections in selected Kenyan hospitals. Results Using a cross-sectional hospital-based approach, the present study evaluated the performance of urine dipstick test in UTI diagnosis using culture as the gold standard. A UTI prevalence of 54.1% was found using culture. This was lower than the 66.4% recorded by the dipstick test. Estimated UTI prevalence by Nitrate test, RBCs, and Leukocyte's esterase (L.E) was 11.9%, 28.1 %, and 46%, which were lower than the observed. The nitrate test had a sensitivity of 19.8%, which was lower than 32.9%, 65.5%, and 66.2% by RBCs, all dipstick parameters, and L.E, respectively. Nitrate test (97.4%) and RBCs (77.6%) had a better specificity compared to L.E (56.5%) and all dipstick parameters combined (68.3%). Conclusion The prevalence discrepancies from the observed and low sensitivity and Specificity imply dipstick test inadequacy for accurate UTI diagnosis. The finding also demonstrates the need for urine culture for accurate UTI diagnosis.

The diagnostic accuracy of the point-of-care urine dipstick test in detecting urinary tract infection among symptomatic patients in Nairobi County, Kenya

“…The test has poor positive predictive value and minimal agreement with culture (kappa, 0.23). The LE sensitivity of 62.2% reported by Maina et al [11], 60% by Dadzie et al [17] and 48% by Anith et al [9] were all higher than the nitrite test, which mirrors that of the present study. Despite being more sensitive than nitrites, the LE test is not specific for UTI and may be associated with other inflammatory disorders affecting the urinary tract such as vaginitis, chlamydial urethritis or other infections than can elicit an immune response and production of white blood cells [32].…”

“…In this study, consideration of urine dipstick positivity as 'either NIT+ or LE+' reported a positivity rate of 34%. This compares to prior dipstick positivity reports of 54% by Maina et al in a similar study in Kenya [11], 73% by Katunzi et al in Tanzania [20] and 34% by Dadzie et al in Ghana [17].…”

“…These limitations have made urine dipstick a more convenient and frequently used first line laboratory investigation for UTI in primary care settings [9]. In many resource-limited settings it is the only test available [10,11].…”

Prevalence of Urinary Tract Infections and Antibiogram of Bacteria Isolated From Children With Sickle Cell Disease in Tanzania

“…Despite these metrics advocating for their use in preliminary screening, the test's limitations necessitate confirmation by culture for a definitive diagnosis. This study highlights the unreliability of dipsticks for accurate UTI detection in children with SCD, noting discrepancies in prevalence rates compared to culture methods and the risk of false results [ 24 , 25 ]. Consequently, clinicians should not rely solely on the dipstick test for UTI screening, emphasizing the need for corroborative diagnostics.…”