Retrospective Application of the Proposed CDC/APHL Rapid Testing Algorithms in New Jersey 2004-7

1. Retrospective Application of the Proposed CDC/APHL Rapid Testing Algorithms in New Jersey 2004-7 Cadoff EM, Cadoff RA, Salaru G, Paul SM, Martin EG Evan M. Cadoff, MD Robert Wood Johnson Medical School New Brunswick, NJ

2. NJHIV Rapid Testing Program • Under direction of RWJMS • OraQuick started November 1, 2003 • Oversees about 2/3 of NJ CTS HIV testing • Confirmatory testing at PHEL in Trenton • NJHIV oversees followup of all discordant • NJHIV does not evaluate linkage to care

3. Preliminary Positive Followup • 7.1% refused blood draw for confirmation • 25.8% of those drawn did not return for results • 70.1% of confirmed positives got their results and post-test counseling • Rapid confirmation could improve effectiveness of prevention and referral/entry to care and treatment services

4. Data Needs for Proposed Testing Strategies • Are there false negative screening tests? • Can true positive screening tests be confirmed by a second rapid test, rather than WB/IFA/NAT? • Can false positive screening tests (ie discordants) be detected by a second rapid test, rather than waiting for WB/IFA/NAT? • Impact on linkage to care? • How well can inconclusive “second-round” test results (eg, WB vs a second rapid test) be resolved?

5. Two NJHIV Datasets • Confirm true positives • Evaluate confirmed false positives • Resolve discordants and indeterminate confirmatory test results

6. Nov 2003 – April 2005 data • Rapid testing by blood only using OraQuick • Western Blot specimens sent to PHEL • All avialable WB specimens evaluated by: • Repeat OraQuick on blood • Trinity Uni-Gold • MedMira Reveal • BioRad Multispot • Followup of clients with discordant results

7. 8 15,923 355 Nov 2003 – April 2005 data • 15,923 OraQuick tests statewide • 363 preliminary postive samples to state lab for Western Blot • 355 Western Blot positive confirmed by other rapids • 8 Western Blot negative discordants • all repeat OraQuick positive • one reactive Multispot by one reader • others all negative • 6 preliminary positive is false positive • 25% with no clinical followup Strategy 1, Data Need 3

8. Discordant followup • Four visits: • Rapid test. If prelim pos, draw blood and send to Trenton for Western Blot. • Return in a week, and get discordant confirmatory test result. • Return at a month to have more blood drawn (repeat antibody; and NAAT). • Come back a week later for definitive result.

9. Discordant followup

10. Revised discordant followup Three Visits • If rapid test is reactive, draw Western Blot. • Return in a week. Get discordant confirmatory test result and draw NAAT. • Third visit for NAAT result. or Two Visits • If rapid test is reactive, draw both Western Blot and NAAT. • NAAT is run if WB is discordant, and both results are available at second visit.

11. Revised discordant followup Three Visits • If rapid test is reactive, draw Western Blot. • Return in a week. Get discordant confirmatory test result and draw NAAT. • Third visit for NAAT result. or Two Visits • If rapid test is reactive, draw both Western Blot and NAAT. • NAAT is run if WB is discordant, and both results are available at second visit. or One visit with rapid confirmation would be better!

12. Jan 2006 – Oct 2007 data • Retained specimens from followup testing for discordant Western Blot results. • Cannot confirm true positives. • Can evaluate discordants and indeterminates (if they had followup).

13. Jan 2006 – Oct 2007 data • Samples are not from the same time as screening OraQuick. • Used CLIA-waived tests: • Repeat OraQuick on blood • Trinity Uni-Gold • Clearview StatPak

14. Jan 2006 – Oct 2007 data 108 false positive; 72 without followup may be false positive [Strategy 1, Data need 3; Strategy 4, Data need 5a] No false positive strategy results [Strategy 4,Data need 1]; No false negative A2 or A3 [Strategy 4, Data need 4, 5b]

15. Jan 2006 – Oct 2007 data No false positive strategy results [Strategy 3, Data need 1] 1 false positive A1-blood result [Strategy 3, Data need 4a,5] 91 false positive A1-oral results [Strategy 3, Data need 5] No false negative A2 results [Strategy 3, Data need 4b]

16. Jan 2006 – Oct 2007 data No false positive strategy results [Strategy 2, Data need 1] 17 Inconclusive results with false positive A1 [Strategy 2, Data need 4]

17. Data Needs for Proposed Testing Strategies • All followups on negative Western Blot were NAAT negative (OraQuick false positive). • All were "second rapid" negative. • Oral OraQuick followed by blood OraQuick: • 3 tested at CTS site on False Positives: • 2 blood negative; 1 blood positive • 56 tested on followup blood specimen • all blood negative • OraQuick blood discordant • 11 tested on followup blood specimen • 7 negative • 4 repeat positive

18. Observations • Indeterminate Western Blot: • 12 total: • 4 no followup; 3 QNS • 3 NAAT negative were "second rapid" negative • 2 NAAT positive were "second rapid" positive

19. Rapid Confirmation Is Needed • Rapid confirmation of preliminary positive results is necessary: • 30-40% without followup would have benefited from rapid confirmatory testing.

20. Rapid Confirmation Works • All 355 true positives confirmed using a second rapid test (from a pool of about 16,000 clients tested) • All 65 false positives with followup available were negative using a second rapid test (from a pool of about 120,000 clients tested) • Indeterminate Western Blots were resolved by a second rapid

21. Conclusions • Rapid confirmation of preliminary positive results is necessary. • Rapid confirmation of preliminary positive results works at least as well as Western Blot testing.