CĂN NGUYÊN VI KHUẨN VÀ HIỆU QUẢ CỦA QUE THỬ NƯỚC TIỂU TRONG DỰ ĐOÁN NHIỄM KHUẨN ĐƯỜNG TIẾT NIỆU

Abstract

Introduction: In most healthcare facilities, the balance between available diagnostic tools for urinary tract infection (UTI) has been addressed by adopting the faster and less labor-intensive urine dipstick test. This study aimed to determine the prevalence of UTI, identify its bacterial etiology, and evaluate the diagnostic performance of the urine dipstick test. Methods: A cross-sectional study was conducted on 367 patients clinically suspected of having UTI at Ninh Thuan General Hospital (4–9/2025). The samples were cultured on blood agar and incubated overnight at 37°C. A bacterial count of ≥10⁴ CFU/mL was considered positive. Urine dipsticks were used to detect nitrite (NIT) and leukocyte esterase (LEU) results ≥ “trace” were considered positive. Quantitative urine culture served as the gold standard for comparison. Results: The prevalence of UTI was 22.9%, with E. coli being the most common pathogen (50%). Multivariate regression analysis revealed that female gender (AOR = 1.8), LEU+ (AOR = 2.3), and NIT+ (AOR = 5.0) were independent factors associated with UTI. The regression model achieved an AUC of 0.738. Regarding diagnostic performance, LEU+ showed the highest sensitivity (61.9%), while NIT+ exhibited very high specificity (93.6%) and an LR+ (Positive Likelihood Ratio) of 4.9. The combination "NIT or LEU" yielded a sensitivity of 64.3%, and the combination "NIT and LEU" showed the highest specificity (95.8%) and an LR+ of 6.7. The Kappa coefficient ranged from low to moderate (0.25–0.3). Conclusion: The combination of NIT and LEU provides better diagnostic performance than either indicator alone; however, confirmation by quantitative urine culture remains necessary in primary healthcare settings.