An interdisciplinary study of diagnostic tools and antibiotic prescribing practice for urinary tract infection in Kenya

Abstract

Urinary tract infections (UTIs) are common globally and antimicrobial resistance (AMR) poses a challenge to effective treatment. AMR is a social-biological problem, so interventions require interdisciplinary approaches. This thesis combined social science and microbiology to investigate UTI diagnosis and management in Kenya, including evaluation of the Scattered Light Integrated Collector (SLIC) for rapid UTI detection and antibiotic susceptibility testing (AST). Healthcare worker interviews were conducted to provide insights into determinants of antibiotic prescribing behaviour. A clinical cross-sectional study was conducted to quantitatively evaluate the performance of standard-of-care tests and SLIC for UTI diagnosis and AST. Further interviews explored the feasibility of introducing SLIC into diagnostic pathways.

Interviews showed that antibiotic prescribing is a complex socially embedded practice, influenced by prescriber beliefs, treatment guidelines, diagnostic uncertainty, patient expectations/pressure, and poor communication between clinical and laboratory teams. Quantitative microbiology identified 124 positive urine cultures from 552 symptomatic patients. Urine dipstick and microscopy results were poorly predictive of positive urine culture, but algorithms combining dipstick results with key urinary symptoms and fever increased the probability of case detection. AMR, determined by disk-diffusion, was common, contributing to inappropriate empirical therapy in 38/95 (40%) of patients. Compared to urine culture, SLIC had UTI-detection sensitivity of 86% (95% CI: 79-91%) and specificity of 98% (95%CI: 96-99%). The agreement between SLIC AST and disk diffusion was 94%, higher than direct susceptibility (DST) which was 82%. SLIC’s DST and AST results were available in 3 hours and 26 hours respectively, highlighting opportunities to shorten UTI diagnostic pathways. Feasibility interviews suggested the need to consider how SLIC implementation impacts structures and professional roles of end-users.

This thesis demonstrates the value of interdisciplinary methods to evaluate novel diagnostic technology in settings of intended use and provides early data on the potential value of SLIC for UTI diagnosis and AMR detection.

Date of Award	2 Jul 2025
Original language	English
Awarding Institution	University of St Andrews
Supervisor	Robert Hammond (Supervisor), Katherine Keenan (Supervisor), Derek Sloan (Supervisor) & Mike Kesby (Supervisor)