Quality assurance practices in tuberculosis diagnostic health facilities in Ethiopia

The quality of tuberculosis laboratory services in health facilities is a mandatory component of detecting active pulmonary TB cases and treatment follow-up. However, ensuring the quality of laboratory test results is a concern. This study aimed to assess the quality assurance practices in the tuberculosis diagnostic health facilities of Ethiopia.

A cross-sectional study was conducted from October 2018 to March 2019 at nine governmental TB-culture laboratories and 34 randomly selected GeneXpert® MTB/RIF (Xpert® MTB/RIF) testing health facilities in Ethiopia. Participating health facilities were interviewed and laboratory documents and records present since 2017 were observed. Prior to the data collection, training was given to the data collectors. Descriptive statistics were used to produce results and were presented with tables and graphs.

From a total of 34 Xpert® MTB/RIF testing laboratories, 50% run Internal Quality Control (IQC) for Acid-Fast Bacillus (AFB) Microscopy and 67.6% had lot-to-lot verification of staining reagents. For the Xpert® MTB/RIF assay, a lot-to-lot verification of cartridge and method validation was performed only in 8.8%and 20.6% of Xpert® MTB/RIF testing laboratories respectively. All TB-culture laboratories included in the study ran negative control (start and end IQC) during TB-culture sample processing and performed lot-to-lot verification for Mycobacteria Growth Indicator Tube (MGIT) in 88.9% of TB-culture laboratories. External Quality Assessment (EQA) Proficiency Testing (PT) for AFB microscopy is practiced in 79.4% Xpert® MTB/RIF testing laboratories and 100.0% for the Xpert® MTB/RIF assay. TB-Culture PT participation practice among TB-culture laboratories was 88.9%. A major challenge for health facilities during PT participation was the AFB PT-sample transportation delay (40.7%) and the Xpert® MTB/RIF assay EQA-PT feedback missing (38.2%).

This assessment reveals that IQC for AFB microscopy, lot-to-lot verification, method validation, and equipment calibration were not well-practiced. The majority of TB diagnostic health facility laboratories had EQA-PT participation practice, but a significant gap in PT-sample transportation and missing feedback was identified.