Abstract
Background Diagnostic uncertainty and poor uptake of diagnostic testing contribute to inappropriate antibiotic use and rising antibiotic resistance, particularly in low- and middle-income countries where infrastructure, workforce, and logistical constraints limit access to diagnostics. South Africa’s mixed public-private health system, marked by resource disparities across provinces, provides an important setting for exploring factors shaping diagnostic adoption. We investigated these factors across different South African health settings to inform strategies for improved infection management and antibiotic stewardship. Methods Between January and May 2023, we conducted in-depth qualitative interviews with 36 stakeholders including leaders from national and provincial health departments, the National Health Laboratory Service, private laboratories, and end-user clinicians. Participants worked across primary, secondary, and tertiary care in urban, peri-urban and rural settings in four purposively selected provinces: Western Cape, Eastern Cape, KwaZulu-Natal and Free State. Interviews were conducted online using a pre-piloted guide and analysed thematically. Results Diagnostic implementation and adoption were shaped by national directives, provincial governance, facility-level practices, and clinician-level factors, with inequities linked to provincial variation in resource and governance capacity. Inefficient procurement, frequent stock-outs, poor infrastructure and planned electricity interruptions undermined diagnostic availability. Human resource shortages, high staff turnover, and limited training undermined diagnostic stewardship, including over-testing and inappropriate use and interpretation by junior doctors. Additional challenges included poor laboratory-clinician communication, outdated equipment, unreliable information systems, and specimen transport delays. Facilities adopted mitigation strategies including backup power systems, pharmacist-led gatekeeping, and digital platforms for rapid result sharing. Conclusion Interconnected governance, infrastructure, workforce, and information-system barriers hinder effective diagnostic implementation across South Africa’s health system, disproportionately affecting under-resourced provinces and rural facilities. Strengthening procurement systems, laboratory infrastructure, workforce capacity, specimen transport networks, and digital surveillance should be prioritised within national antimicrobial resistance action plans to support rational antibiotic use and mitigate the growing threat of antibiotic resistance. Trial registration Not applicable.