The nature and frequency of pre-analytical errors in Tuberculosis (TB) specimen processing across major diagnostic institutions in Johannesburg

This study examines pre-analytical errors in tuberculosis (TB) specimen processing across four major hospitals in Johannesburg during the COVID-19 pandemic (March 2021–March 2022). Using a retrospective observational design, 649 rejected TB specimens were analysed to determine the main causes, trends, and institutional differences in error occurrence. The results identified specimen inadequacy as the most common cause of rejection, followed by duplicate test requests and sample leakage. Error rates varied across months and institutions, with statistical analysis confirming significant associations between healthcare facilities and error types. The study highlights critical weaknesses in the pre-analytical phase of TB diagnostics, emphasizing the need for improved specimen collection, strengthened administrative processes, and targeted staff training. Addressing these challenges is essential to enhance diagnostic accuracy, reduce delays in treatment, and improve patient outcomes in high-burden, resource-limited settings.