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Laboratory QA/QC methods for ANC based HIV sentinel surveillance (Ethiopia): Experience from 2007 survey Desta Kassa (BSc, MSc, PhD student) (On behalf of: EHNRI/Regions/CDC, WHO - Ethiopia) 2 nd Global HIV surveillance Meeting 2-5 March, 2009 Bangkok, Thailand. The presentation:.

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  1. Laboratory QA/QC methods for ANC based HIV sentinel surveillance (Ethiopia): Experience from 2007 surveyDesta Kassa (BSc, MSc, PhD student)(On behalf of: EHNRI/Regions/CDC, WHO - Ethiopia)2nd Global HIV surveillance Meeting 2-5 March, 2009 Bangkok, Thailand

  2. The presentation: • HIV/AIDS in Ethiopia II) QA/QC methods applied 1. Planning/Coordination/Implementation 2. Sample management and HIV testing 3. Quality control (QC) . Proficiency testing (EQA) . Sample re-testing III) QA/QC Results IV) Summary VI) Challenges VII) Acknowledgments

  3. I) HIV/AIDS in Ethiopia • Area: 1.1 km2 • Population:77 million • Administrative set up:9 Regions and 2 City Adm • First evidence of HIV infection: 1984 • First two AIDS case reported : 1986 • Predominant HIV-1 subtype:C • Main transmission mode :Heterosexual • Surveillance started: 1989 • HIV Prevalence of the 2005 surveys : • ANC: 3.2% • DHS+: 1.4% • Single point: 2.1% • PLWHA : 1.3 million • People Need ART: 277,000 • People on ART (currently) : 175612 (128935)

  4. No. ANCSites ANC &Testing sites in 2007 70 38 20 Referral Lab/EHN RI ANC Sentinel Surveillance Sites (1989-2007)

  5. II) QA/QC methods Applied 1.Planning/Implementaion/Coordination

  6. National serosurvey operational structure FMOH FHAPCO EHNRI/Referral lab National TWG Donors: CDC, WHO . EHINRI . CDC . WHO . UNAIDS . USAID . CSA . Tulane University Regional Health Bureaus Federal Army and Police sites Regional HIV testing sites ANC Sites

  7. 2) Planning/implementation/coordination .FMOH/EHNRI . Regions/Donors (CDC/WHO) National Planning Workshop TOT to Regions ANC sites Training HIV Testing sites Review meeting Site assessment supply distribution Execution (5 months) Supervision ( 2x) (EHNRI/Regions/CDC/WHO) Data analysis & Reporting (AIDS In Ethiopia)

  8. 3. Sample management: ANC sites-Testing sites-Referral Lab

  9. ANC sites (n=108) (Samples & Forms every 2 weeks) Regional HIV Testing sites (n=20) Forms: . Reporting form . Tally sheet . Code ranges . Temperature Recording . OD recording Check Specimen quality/quantity Reject if sample: Checking of perfect match . Not 1.8 ml Nunk tube . Not in Cryoboxes . Not in cold boxes . Not in 1-8 0C) . Quantity: < 250 or 350 . Volume: < 0.75 ml . Haemolysed . Bacterial/Fungal overgrowth . Stored warm: > 9 c HIV Testing (ELISA) HIV Testing (Viro Ag/Ab,.. Murex Ag/Ab) . All Pos . 10% Neg . All indeterminate . Transport control QC: Referral lab (EHNRI) Check sample quality & Forms

  10. 1. Proficiency testing (EQA) (In-house & transport controls)2. Re-testing surveillance samples (previous slide) 3. QC methods

  11. Known pos plasma: ELISA + WB Titrated: 1:5120 Mean OD:0.272 (95% CI: 0.244 -0.299) Aliquots as: Transport control In-hose control Test at Sites Sent to Testing Sites Store at EHNRI Result sent to EHNRI Sent back with samples to EHNRI Test at EHNRI Results compared with EHNRI Indicate status of: . Expertise . Machinery . Pipettes OD compared with EHNRI Indicate specimen storage/Transport status from sites 1. Proficiency testing (In-house & transport controls)

  12. A= Concordance in positives B = Concordance in Negatives C= Concordance in Indetermi D= Over all Concordance • 2. Re-testing surveillance samples at referral lab • All positives • 10% Negatives • All indeterminates • Transport control 3. QC methods……Cont’d D

  13. III) QA/QC Results (2007 survey) 1. Samples Quantity/Quality

  14. Samples collected/Region Samples sent for QC test 1) Sample quantity/quality .Sites collected optimal sample size: 101/108 (93.5%) . Total samples collected: 36350 (350 samples/site) . Total samples rejected : 130 (0.35%)

  15. III. QA/QC Results … cont’ 2) Proficiency testing: The Transport controls • Storage condition at Testing sites • Transportation from Testing sites to the Referral lab

  16. No major storage and Transportation problem in all Regions !

  17. IV. QA/QC Results … cont’ 2) Proficiency testing (EQA): The in-house controls Performance of the Regional Testing sites The analysis: • Accuracy (Comparing the mean OD value) • Precision (Comparing reproducibility of the OD value, CV < 20 %) • Proportion of positive results (100%?)

  18. 2) Proficiency Testing: The In-house control (Accuracy-mean OD)Referral Lab: Mean OD : 0.273 [ 95% CI: 0.161 – 0.385]

  19. Regional Testing sites The in-house controls:precision (CV < 20%)

  20. Testing sites In-house controls:proportion of positives results

  21. III. QA/QC Results … cont’ 3. Re-testing of the surveillance samples at Referral lab

  22. All pos + Neg + Inde Testing sites Test agreement between Testing sites vs. Referral Lab

  23. Test agreement between Referral lab vs Regions (2005/2007)

  24. Criteria for Accepting/Rejecting Regional Test Results • Test result agreement Referral lab vs. Regions • >=95% concordance in the positives or Negatives : Results of Testing site will be taken • < 95% concordance in the positives or Negatives: Results of Referral Lab will be taken • For the indeterminate: Results of the Referral Lab II) Results of the proficiency testing ( In-house controls)

  25. VI) Summary and conclusions • Samples/data collected were at good quality (0.35% rejected) • Improvement in technical performance of testing sites • No major storage or transportation problem of samples • Strong collaboration among national institutes and donor agencies contributed significantly for data quality • Improvement in sample/data quality (2005 – 2007)

  26. VII) Challenges • Future direction of ANC based HIV surveillance • ART, PMTCT, VCT • Increasing data quality • increase in Rural sites . Incidence assay as a solution ? • Cut-off value for measuring quality of laboratory data(Concordance between referral lab and Testing sites 95% ?)

  27. VIII) Acknowledgements • EHNRI • Regions • Regional Labs • CDC-Ethiopia • WHO-Ethiopia • National TWG

  28. Thank you

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