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Protecting the quality of HIV testing in the new HIV testing environment

Protecting the quality of HIV testing in the new HIV testing environment. 20 th International AIDS Conference 24 July 2014, Melbourne Anita Sands Prequalification Team – Diagnostics Department of Essential Medicines & Health Products. Background. Quality of all HIV testing is a priority

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Protecting the quality of HIV testing in the new HIV testing environment

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  1. Protecting the quality of HIV testing in the new HIV testing environment 20th International AIDS Conference 24 July 2014, MelbourneAnita Sands Prequalification Team – DiagnosticsDepartment of Essential Medicines & Health Products

  2. Background • Quality of all HIV testing is a priority • Incorrect HIV testing results will occur without a framework to guide quality of testing • 3 C's to the 5 C's • Consent • Confidentiality • Counselling • Correct test results • Connection/linkage to prevention, care and treatment

  3. Where to deliver HIV testing Universal access to HTC Facility based HTC Community based HTC Home-based PITC Clinical settings Outreach (key pop) Other facilities e.g. stand-alone VCT Events Workplace Schools Quality standards for all HTC settings

  4. Framework for quality of HIV testing List of prequalified diagnostics National regulatory framework for diagnostics Guided by Selection of testing strategy Guided by National testing and QA policies Training Quality assurance Validation of testing algorithm(s) Procurement of diagnostics Supported by Post-market surveillance

  5. WHO Prequalification of Diagnostics Pre-submission form Priority product No Yes Dossier screening Dossier incomplete Dossier complete Dossier review Site inspection Laboratory evaluation Prequalification decision

  6. Framework for quality of HIV testing List of prequalified diagnostics National regulatory framework for diagnostics Guided by Selection of testing strategy Guided by National testing and QA policies Training Quality assurance Validation of testing algorithm(s) Procurement of diagnostics Supported by Post-market surveillance

  7. Testing strategy for diagnosis: high prevalence >5% Conduct A1 Result: A1+ Result: A1- Report: HIV negative Conduct A2 Result: A1+ A2- Result: A1- A2- Report: HIV negative Repeat A1 and A2 Result: A1+ A2+ Report: HIV positive Result: A1+ A2- Conduct A3 Source: HIV Assays Report 17 http://apps.who.int/iris/bitstream/10665/93679/1/9789241506472_eng.pdf Result: A1+ A2- A3+ Report: HIV inconclusive Result: A1+ A2- A3- Report: HIV negative

  8. Testing strategy for diagnosis: low prevalence <5% Conduct A1 Result: A1+ Result: A1- Report: HIV negative Conduct A2 Result: A1+ A2 - Result: A1+ A2 - Report: HIV negative Repeat A1 and A2 Result: A1- A2 - Report: HIV negative Result: A1+ A2 + Conduct A3 Source: HIV Assays Report 17 http://apps.who.int/iris/bitstream/10665/93679/1/9789241506472_eng.pdf Result: A1+ A2+ A3+ Report: HIV positive Result: A1+ A2+ A3- Report: HIV inconclusive

  9. Framework for quality of HIV testing List of prequalified diagnostics National regulatory framework for diagnostics Guided by Selection of testing strategy Guided by National testing and QA policies Training Quality assurance Validation of testing algorithm(s) Procurement of diagnostics Supported by Post-market surveillance

  10. Validation of testing algorithms • How to chose the assays to be used as Assay 1, Assay 2, and Assay 3? • Assay 1 = most sensitive • Assay 2 and Assay 3 = most specific • Poor choice of Assay 2 and 3 may lead to high rates of misclassification • Defined national testing algorithms • With back-up options in case of stock-outs or product failures

  11. (Un) clear test instructions • Example of HIV diagnostic rapid test procedure: • Using one of the disposable pipettes supplied, fill with specimen. • Holding the pipette over the specimen well, add two drops of specimen (approx. 50μl). • Add 2 drops of buffer (approx. 60μl) to specimen well. • Allow 5 – 20 minutes from the time of buffer addition for the reaction to occur. For strongly positive results, the test line may become visible earlier. It is advisable to wait the full 20 minutes for negative results.

  12. Critical parts of test procedure • Volume of specimen • Too little = reduced sensitivity • Volume of buffer • Too much = test may overflow • Too little = specimen will not flow through the device • Reading time • Too soon = high background • Too late = reduced specificity

  13. WHO post-market surveillance • WHO is developing guidance for both reactive and proactive elements of post-market activities • End-users, manufacturers, NRAs all have a role WHO prequalified product Reactive PMS Proactive PMS Complaints Lot verification testing Field Safety Corrective Action Field Safety Notice

  14. Framework for quality of HIV testing List of prequalified diagnostics National regulatory framework for diagnostics Guided by Selection of testing strategy Guided by National testing and QA policies Training Quality assurance Validation of testing algorithm(s) Procurement of diagnostics Supported by Post-market surveillance

  15. Quality assurance Organization Personnel Equipment Process Control Quality Control & Specimen Management Information Management Purchasing & Inventory Occurrence Management Assessment Documents & Records Process Improvement Customer Service Facilities & Safety • Using ISO 15189 as the standard and CLSI GP26-A4 as guidance • External quality assessment (EQA) • Verifies the proficiency of the testing process • Quality Control (QC) • Verifies the test is working correctly

  16. Assuring quality of community-based HTC • Keep the service delivery model simple • Community workers (operators) must be trained and proficient in specimen collection, test procedure, reading of results, and interpreting results • Support from the laboratory is crucial • Ensure linkage to treatment and care • For additional testing to confirm the diagnosis, and preferably at a site that performs treatment assessment i.e. CD4 count for ART initiation

  17. Framework for quality of HIV testing List of prequalified diagnostics National regulatory framework for diagnostics Guided by Selection of testing strategy Guided by National testing and QA policies Training Quality assurance Validation of testing algorithm(s) Procurement of diagnostics Supported by Post-market surveillance

  18. Training and proficiency • Competency-based training • Proof of proficiency with panel of HIV + and HIV - specimens • Proficiency for the entire testing algorithm, not just test procedure • Simple SOPs • Easy to read job aids

  19. WHO normative guidance • WHO service delivery approaches to HTC: a strategic policy framework • http://apps.who.int/iris/bitstream/10665/75206/1/9789241593877_eng.pdf • WHO handbook for improving HIV testing and counselling services • http://www.who.int/hiv/pub/vct/9789241500463/en/index.html

  20. WHO/CDC training package • Training package • Participants manual • Trainers guides • Visual aids • Requires local adaptation Undergoing revision • http://www.who.int/diagnostics_laboratory/documents/guidance/hivrttraining_overview/en/index.html

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