Genexpert MTB/RIF diagnostic and tuberculosis treatment initiation delays in Namibia

Abstract

BACKGROUND : Early diagnosis and treatment of drug resistant tuberculosis are crucial in the control of the disease and treatment success. In Namibia, there is a gap in empirical data on the diagnosis and treatment initiation delay time since the roll-out of the GeneXpert MTB/RIF (Xpert) assay in 2017. This study aimed to determine Xpert pre-diagnosis and turnaround time at Namibian Institute of Pathology (NIP) as well as rifampicin resistant tuberculosis (RR-TB) treatment initiation delay on patients admitted at Katutura Intermediate Hospital TB clinic. METHODS : This was retrospective descriptive cross-sectional study which was conducted from 1 July 2018 to 31 March 2019. A total of seventy two participants comprising of twenty five RR-TB and forty seven non RR-TB patients were enrolled using consecutive sampling method. Laboratory information system (LIS) was utilized to determine Xpert median pre-analytical delay and turnaround time. Patients’ records and LIS were used to calculate median treatment initiation delay time post Xpert diagnosis. Data on continuous variables was summarized as median and interquartile range. RESULTS : The median pre-diagnostic, diagnostic and treatment initiation delay time were 7.5 (IQR: 0-14), 1 (IQR: 0-3) and 10 (IQR: 1-32) days respectively for RR-TB. For drug susceptible TB, the median pre-diagnostic, diagnostic and treatment initiation delay time were 5 (IQR: 1-8), 1 (IQR: 0-3) and 3 (IQR: 0-12) days respectively. Overall, median health system delay time was 21 (IQR: 2-32) days for RR-TB patients and 12 (IQR: 1-12) days for non RR-TB patients. CONCLUSION : Treatment initiation to appropriate second line regimes was long for many patients and may be attributable to poor interpretation of discordant results and increased number of RR-TB patients for treatment since Xpert adoption. Unnecessary referrals due to shortages of pulmonologists, cumbersome baseline investigations and outdated guidelines and policies could be the determinants of health system delay time. Interventions targeted at addressing identified factors should be implemented. Further studies should explore the actual treatment gap among RR-TB patients and further risk factors for delayed treatment.