Assuring Quality in COVID-19 Testing
- Quality is the degree to which preset standards are met
- Quality laboratory results are accurate, reliable and timely
- Benefits of assuring quality in COVID-19 testing includes:
- Monitors all parts of the testing system
- Detect and reduce errors
- Improve consistency between testing sites
I. Common Quality Assurance related challenges facing molecular diagnostics
- Assay Sensitivity – Variability, relatively high detection limits of some methods
- Clinical significance - quantitative analysis / reporting / ‘setting cut-off levels’
- Variable NA isolation procedures – limited integration
- Standardization of reagents – in-house versus commercial methods
- Standardization & control of molecular assays – use of appropriate controls
- Lack of appropriate control material
- General Result Reporting – units used / nomenclature used
- Operator kill and competence
- Inadequate documentation
- Storage and handling of reagents
- Handling and maintenance of equipment
II. Quality Control for COVID-19 testing
- Validation or verification
- Alternatively, use interlaboratory comparison with EPHI
- QC included in each run and to cover each critical step
- Extraction negative control
- Extraction positive control
- No template controls
- Positive template control(s)
- Alternative QC
- Negative control: Water/universal transport media/viral transport media
- Positive control: A patient sample with a known (and preferably low 25-30) Ct value (virus concentration) for human gene target e.g., RNAse P or non-human, non-SARSCoV-2 extraction control e.g. Equine Arteritis virus