A global proficiency testing programme for Xpert® MTB/RIF using dried tube specimens, 2013-2015.

Area of Science:

• Clinical diagnostics
• Microbiology
• Public health laboratory science

Background:

• Proficiency testing (PT) is crucial for ensuring accurate diagnostic results in clinical and public health laboratories.
• The Xpert® MTB/RIF assay is widely used for tuberculosis detection, particularly in resource-limited settings (RLS).
• A lack of low-cost PT materials hinders external quality assessment (EQA) for the Xpert MTB/RIF assay in RLS.

Purpose of the Study:

• To evaluate the feasibility of a dried tube specimen (DTS)-based PT program for Xpert MTB/RIF EQA in RLS.
• To assess the demand for Xpert MTB/RIF PT materials in RLS.
• To determine if participation in a DTS-based PT program improves country-level performance.

Main Methods:

• A voluntary EQA program using DTS-based PT material was developed and conducted between 2013 and 2015.
• Eight PT rounds, each with five DTS samples, were distributed to participating testing sites.
• Participant results were compared to expected results, scored, and performance reports were provided.

Main Results:

• Program enrollment grew significantly, from 102 sites in seven countries to 441 sites in 14 countries over three years.
• Approximately 90% of participating sites achieved satisfactory performance in each PT round.
• Seven of the 14 countries showed an increase in satisfactory performance scores over time.

Conclusions:

• An Xpert MTB/RIF PT program using DTS is feasible for RLS.
• There is substantial demand for Xpert MTB/RIF PT materials in RLS.
• Country performance in Xpert MTB/RIF testing can be improved through a DTS-based PT program.