Impact of External Quality Assurance on the Quality of Xpert MTB/RIF Testing in Viet Nam

Abstract

Following the endorsement of the Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA, USA) by the World Health Organization (WHO) in 2010, Viet Nam’s National Tuberculosis Control Program (NTP) began using GeneXpert instruments in NTP laboratories. In 2013, Viet Nam’s NTP implemented an Xpert MTB/RIF external quality assurance (EQA) program in collaboration with the U.S. Centers for Disease Control and Prevention (CDC) and the Foundation for Innovative New Diagnostics (FIND). Proficiency-testing (PT) panels comprising five dried tube specimens (DTS) were sent to participating sites approximately twice a year from October 2013 to July 2016. The number of enrolled laboratories increased from 22 to 39 during the study period. Testing accuracy was assessed by comparing reported and expected results; percentage scores were assigned; and feedback reports were provided to sites. On-site evaluation (OSE) was conducted for underperforming laboratories. The results from the first five rounds demonstrate the positive impact of PT and targeted OSE visits on testing quality. On average, for every additional round of feedback, the odds of achieving PT scores of ≥80% increased 2.04-fold (95% confidence interval, 1.39- to 3.00-fold). Future work will include scaling up PT to all sites and maintaining the performance of participating laboratories while developing local panel production capacity.

Implementation of GeneXpert MTB/Rif proficiency testing program: A Case of the Uganda national tuberculosis reference laboratory/supranational reference laboratory

“…These were related to human error, equipment maintenance, staff training and competency, environment and procedures being used. To a less extent, a false result could be attributed to the PT preparation process regardless of the rigorous quality control procedures undertaken as highlighted by other PT studies [ 27 ] and not the case in this one. Therefore, to unearth the possible cause of performance failure in a PT, one has to holistically do unbiased root cause analysis and identify the only possible cause if it is not so obvious.…”

“…Recent studies in Africa show that the laboratory fraternity and test quality for all types of clinical laboratories remain poorly established [ 9 , 10 ]. EQA in TB performing laboratories is implemented through; onsite support supervision, blinded rechecking, and proficiency testing (PT) [ 11 ].…”

Construction and application of a heterogeneous quality control library for the Xpert MTB/RIF assay in tuberculosis diagnosis

“…Like all diagnostic tests, a quality assurance program based on a proficiency test panel is required to ensure the quality of the Xpert MTB/RIF assay; nevertheless, the development of proficiency test panels has not kept pace with the expansion of Xpert MTB/RIF testing. A limited number of panels are available, most of them derived from M. tuberculosis, including clinical isolates with drug resistance (Scott et al, 2011;Scott et al, 2014;Gumma et al, 2019), which raises important biosafety concerns and constraints in transportation, especially cross-border transportation. The infectious nature of the pathogen imposes specific infrastructure requirements.…”

“…The infectious nature of the pathogen imposes specific infrastructure requirements. A biosafety level III laboratory and associated equipment are prerequisites for preparing these panels (Gumma et al, 2019;Klein et al, 2020), which are not easily accessed in resource-limited settings, hindering the local manufacture of the proficiency test panels, especially in resource-limited regions and countries that are severely affected by TB. In practice, however, local manufactures are encouraged to improve the performance quality of the assay by reducing costs and output time, while ensuring sustainability (Gumma et al, 2019).…”

“…A biosafety level III laboratory and associated equipment are prerequisites for preparing these panels (Gumma et al, 2019;Klein et al, 2020), which are not easily accessed in resource-limited settings, hindering the local manufacture of the proficiency test panels, especially in resource-limited regions and countries that are severely affected by TB. In practice, however, local manufactures are encouraged to improve the performance quality of the assay by reducing costs and output time, while ensuring sustainability (Gumma et al, 2019). Another critical issue needing attention is that M. tuberculosis has an extremely slow growth rate, leading to a period of several months in production and inactivation verification (Scott et al, 2011;Gumma et al, 2019).…”