Rapid HIV Testing and Its Role in Advancing HIV Prevention: 2004 Update

1. Rapid HIV Testing andIts Role in Advancing HIV Prevention:2004 Update Bernard M. Branson, M.D. Chief, Lab Determinants and Diagnostics Section Centers for Disease Control and Prevention

2. Three FDA-approved Rapid HIV Tests

3. Three FDA-approved Rapid HIV Tests

4. OraQuick: Fingerstick, whole blood

5. Obtain finger stick specimen…

6. … or whole blood

7. Loop collects 5 microliters of whole blood

8. Insert loop into vial and stir

9. Insert device; test develops in 20 minutes

10. Reactive Control Positive HIV-1 C C T T Positive Negative Read results in 20 – 40 minutes

11. Requirements for OraQuick Testing • Sold only to “clinical laboratories” • To perform CLIA-waived tests, entities must: • Enroll in CLIA program • Obtain a Certificate of Waiver • Pay a biennial fee • Follow manufacturers’ instructions • Meet state requirements

12. Requirements for OraQuick Testing • Have an adequate quality assurance program • Assurance that operators will receive and use instructional materials • QA guidelines for OraQuick testing and sample forms: www.cdc.gov/hiv/rapid_testing

13. Oral fluid specimens: Reduce hazards, facilitate testing in field settings

14. Reveal HIV-1 Rapid Antibody Test: Serum, Plasma

15. Centrifuge to obtain serum or plasma

16. Add 20 drops of buffer to reconstitute conjugate. (Refrigerate to store)

17. Add 3 drops buffer to moisten membrane

18. Add one drop of serum or plasma, followed by 3 drops of buffer.

19. Add 4 drops of conjugate solution

20. Add 3 drops of buffer to wash

21. Negative Positive Read results immediately

22. Uni-Gold Recombigen: Serum, plasma, whole blood

23. Add 1 drop specimen to well

24. Add 4 drops of wash solution

25. Read results in 10 minutes

26. Point-of-Care Testing • To expand testing in non-clinical settings: • Fingerstick or oral fluid specimen • One-step • Easy to interpret • Internal control

27. The Need for Training • Blood & body fluid precautions • Obtaining the specimen (finger stick or blood draw) • Performing the test • Providing test results and counseling • Quality assurance • OSHA requirements

28. Remember the tradeoffs… • Good News: More HIV-positive people receive their test results. • Bad News: Some people will receive a false-positive result before confirmatory testing.

29. Reports from the 2003 HIV Prevention Conference • Promising news with rapid HIV tests for – • Routine screening in medical settings • Increasing receipt of results at CT sites • Screening in labor and delivery • Outreach testing

30. Routine HIV Screening in Medical Care Settings • Cook County Hospital ED, Chicago • OraQuick testing since October 02 • 60% accept HIV testing • 98% receive test results • 2.8% new HIV positive • 80% entered HIV care • Now underway in Chicago, Boston, Los Angeles • 4 new demonstration projects (Wisconsin, Massachusetts, Los Angeles, New York)

31. HIV Screening in Acute Care Settings • Cook County ED, Chicago 2.3% • Grady ED, Atlanta 2.7% • Johns Hopkins ED, Baltimore 3.2% HIV testing sites 1.3% New HIV+

32. HIV Screening with OraQuick in Labor and Delivery: the MIRIAD Study • Testing of pregnant women in labor for whom no HIV test results are available; 12 hospitals in 5 cities: Atlanta, Chicago, Miami, New Orleans, New York • To date • 4597 women screened • 34 new HIV infections identified • 2 false positive OraQuick tests, no false negatives • 8 false-positive EIAs

33. Turnaround Times for Rapid Test Results,Point-of-Care vs Lab Testing • Point-of-care testing: median 45 min • (range 30 min – 2.5 hours) • Same test in Laboratory: median 3.5 hours • (range 94 min – 16 hours) MMWR 52:36, Sept 16, 2003

34. OraQuick Outreach to High-risk Persons of Color • On-site testing at sites throughout the community • Group pretest counseling. • Individual testing and post-test counseling. Patrick Keenan MD University of Minnesota Medical School Department of Family Practice and Community Health

35. OraQuick Fingerstick Results:7/02 – 6/03 N = 1021 • Preliminary positive 5 (0.5%) • True positives 4 (0.4%) • False Positives 1 (0.1%) • Sensitivity 4/4 (100%) • Specificity 1016/1017 (99.9%) • Positive Predictive Value 4/5 (80%)

36. Results • 99.7% of clients received their test results and post-test counseling. • The average time between fingerstick and learning test result was 28 minutes.

37. Client Survey Results • “I would rather have my finger stuck than have blood drawn from my vein” Agree or strongly agree = 95% Disagree or strongly disagree = 5%

38. Post-Marketing Surveillance • 14 states in 2003, expansion in 2004 as more project areas implement rapid testing • (Note: Supplement to Program Announcement) • Monitoring: • Changes in utilization of testing • Acceptance (choice of tests) • Client and counselor satisfaction • Follow-up on false-positives • Adverse events

39. Initial Observations • 95% of persons opt for the rapid HIV test; 34% of those tested say they would not have been tested if rapid test not available (New York) • In one clinic for homeless persons, HIV prevalence among those tested rose from 4% to 12% after introduction of rapid tests (San Francisco) • 30% of the number of HIV-positive persons identified in all of last year were identified in the first month rapid testing was introduced (Utah) • 98% - 100% of those tested receive their test results

40. Post-Marketing Surveillance • In New York State test sites: 30% increase in persons tested • 85% increase in MSM • 42% increase in IDU • 96% increase in persons with hx of STD diagnosis • Counselors’ • confidence in their overall role in rapid testing rose from 54% to 100% after first 12 weeks of testing • scores on proficiency specimens at 12 weeks were 100%

41. Confirmatory Testing • For Western blot: • Venipuncture for whole blood • Oral fluid specimen • Dried blood spots on filter paper • Confirmatory test essential (not just EIA!)

42. Additional Resources General and technical information (updated frequently): www.cdc.gov/hiv/rapid_testing

44. Interpreting Rapid Test Results For a laboratory test: Sensitivity: Probability test=positive if patient=positive Specificity: Probability test=negative if patient=negative Predictive value: Probability patient=positive if test=positive Probability patient=negative if test=negative

45. Example: Test 1,000 persons Test Specificity = 99.6% (4/1000) HIV prevalence = 10% True positive: 100 False positive: 4 Positive predictive value: 100/104 = 96%

46. Example: Test 1,000 persons Test Specificity = 99.6% (4/1000) HIV prevalence = 10% True positive: 100 False positive: 4 Positive predictive value: 100/104 = 96% HIV prevalence = 0.4% True positive: 4 False positive: 4 Positive predictive value: 4/8 = 50%

47. 10% 99% 98% 92% 5% 98% 96% 85% 2% 95% 91% 69% 1% 91% 83% 53% 0.5% 83% 71% 36% 0.3% 75% 60% 25% 0.1% 50% 33% 10% Positive Predictive Value of a Single Test Depends on Specificity & Varies with Prevalence Predictive Value, Positive Test OraQuick EIA Reveal HIV Prevalence 99.9% 99.8% 99.1% Test Specificity