Diagnostic Performance of Urine Nitrite Testing for Bacterial Urinary Tract Infection Compared to Culture at Enugu State University Teaching Hospital, Enugu, Nigeria.

Publication Details

Publication Date

10/08/2026

Volume / Issue

Vol 1, Issue 3 (2026)

Article No.

068

Journal

British Journal of Contemporary Research

DOI

https://doi.org/10.67693/BJCR-5JSBKYER

Received

31 Jul 2026

Views

37

Downloads

13

Abstract

Background: Urine point-of-care testing, using dipstick technology for nitrite is important for empirical therapy, more especially in a resource limited setting, but analytical pathogen specific sensitivity and specificity performance data from Nigeria are limited. Methods: a cross-sectional study was conducted on 100 urine samples from patients attending Outpatient’s Clinic of the Enugu State University Teaching Hospital, Nigeria, from February to April, 2026. Nitrite was assessed using Medit-test Combi 11 [Macherey-Nagel, Germany] in accordance with the manufacturer instructions. Positive nitrite was described as clear pink dis-colouration on the dipstick test strip. Quantitative urine culture was used as reference standards, and significant bacteriuria was defined as >10 bacterial colonies of a pure/predominant isolate on CLED agar, corresponding to ≥10⁴ CFU/mL. Sensitivity, specificity, predictive values, and likelihood ratios with 95% confidence intervals were calculated using SPSS v26. Results: UTI prevalence was 77% [77/100]. Nitrite demonstrated sensitivity 19.4% [95% CI: 11.1–30.5%], specificity 100% [85.2–100%], positive predictive value 100%, negative predictive value 29.9%, positive likelihood ratio ∞, and negative likelihood ratio 0.81 for culture-confirmed UTI. Among 13 nitrite-positive samples, 10 [76.9%] were Escherichia coli, 2 [15.4%] Staphylococcus aureus, and 1 [7.7%] Klebsiella spp. Nitrite missed 34/44 [77.3%] E. coli and 23/25 [92.0%] S. aureus UTIs. Conclusions: In this study, nitrite is a highly specific surrogate marker for E. coli UTI but lacks sensitivity for all-cause UTI due to high prevalence of nitrite-negative S. aureus and Enterococcus spp. Negative nitrite cannot exclude UTI. With negative nitrite, empiric therapy should consider Gram-positive uropathogens.

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