MODS accreditation process for regional reference laboratories in Peru: validation by GenoType® MTBDRplus.

Area of Science:

• Clinical microbiology
• Infectious disease diagnostics
• Laboratory quality assurance

Background:

• Limited focus on technical aspects for quality-assured implementation of new tuberculosis (TB) and multidrug-resistant TB (MDR-TB) diagnostics.
• Development of a laboratory accreditation process for the Microscopic-Observation Drug Susceptibility (MODS) methodology in Peru.
• Utilizing an expert reference laboratory (UPCH) as the standard for accrediting implementing laboratories.

Purpose of the Study:

• To evaluate the validity of a MODS-based accreditation process.
• To assess the concordance of MODS drug susceptibility testing (DST) with molecular testing methods.
• To ensure high-performance standards for patient care in routine TB diagnostics.

Main Methods:

• Head-to-head comparison of MODS DST results from Peruvian regional laboratories and an expert laboratory (UPCH).
• Comparison of MODS DST results with GenoType® MTBDRplus molecular testing.
• Evaluation of phenotypic drug susceptibility testing (RMP and INH) concordance.

Main Results:

• High concordance between MODS and GenoType MTBDRplus for rifampicin (RMP) DST (97.1%-97.9%).
• Significant concordance between MODS and GenoType MTBDRplus for isoniazid (INH) DST (94.6%-95.7%).
• Consistent high performance across implementing laboratories and the expert reference laboratory.

Conclusions:

• The MODS-based accreditation process is valid for ensuring quality-assured TB diagnostics.
• High concordance between MODS and molecular methods (MTBDRplus) supports their use in accreditation.
• Rapid diagnostic methods can serve as reliable reference standards for laboratory accreditation.