1. California Clinical Laboratory Association
New HIV Diagnostic Testing Algorithm November 8, 2012
Beatrice O’Keefe, Chief
Laboratory Field Services
California Department of Public Health

2. Good Morning

3. New HIV Algorithm Rationale for New HIV Strategy HIV Algorithm
Lab Issues
Challenges

5. Goals of the National HIV/ AIDS Strategy
Reduce The Number of New HIV/AIDS Infections
Increase access to care for people living with HIV/AIDS
Reduce HIV related Health Disparities

6. “Endemic”
Source: HIV/AIDS Surveillance Summary, data as of March 2011.

7. Continuum of HIV Care from Diagnosis to Viral Suppression
80%
62%
41%
36%
28%

8. California respondents
Where Tested for HIV?
California respondents
Source: CDC Behavioral Risk Factor Surveillance System (BRFSS); telephone health survey
Don’t know responses not shown; denominator is those who ever tested for HIV

9. 1989: State of the Art
Western blot
ELISA

10. Progression of Algorithms
1989: CDC recommends 2 test algorithm
T1: HIV EIA nonreactive report as HIV neg
HIV Reactive perform Western blot or IFA
T2: WB or IFA
neg-report as neg
Indeterminate-report as indeterminate
Pos-report as HIV-1 Pos

11. 1989 State of the Art

12. Progression of Algorithms
1992: Last Update to Algorithm
T1-HIV-1/HIV-2 EIA
Non-reactive-report as HIV neg
Reactive-T2 WB or IFA
T2-WB or IFA
Neg-report as HIV neg
Indeterminate-Report as indeterminate
Pos-Report as HIV-1pos

13. Problem s Eliza + not always confirmed HIV-2 not detected
Expensive follow up

14. HIV-2 Importance 242 cases since 1988 66% in Northeast
46% in New York City
81% born in West Africa
HIV-2 cross reaction with HIV-1

15. Progression of HIV Viral Markers
HIV RNA appears almost immediately-peaks at 28 days
P24 antigen appears almost immediately - peaks at 28 days
IgG comes up at 21 days, peaks at 49 days
Symptoms appear at about 14 days and peak at 28 days.

16. New Strategy Needed 20% HIV infected persons unaware of status
Approx 52% of new sexually-transmitted infections involve infected persons unaware of HIV status
Includes 11% due to persons in acute phase of HIV infection
Early Detection beneficial for clinical care and prevention

17. Strategic Plan Developed
2009 APHL & CDC status report
2010 HIV Diagnostics conference
2011 CLSI published criteria

19. Rationale for New Algorithm
Expanded testing and earlier detection needed to reduce HIV infections
New tests can detect acute & early HIV infection
False positives occur with all types of initial tests
WB is not able to confirm acute infections detected by 4th generation Ag/Ab tests
Existing algorithm does not provide good options for resolving discrepant or false-positive results
HIV-2 cross-reactivity on HIV-1 WB confuses interpretation

22. Multi-test Algorithm ● Test 1: Initial test
Previously the screening test
3rd or 4th generation EIA or CIA
● Tests 2 & 3: Supplemental tests
−WB replaced by these 2 tests
● No Confirmatory Test
−Combination of test results used to determine HIV infection status

23. 4th Generation Ag/Ab test
2 FDA approved Kits available
Detects HIV-1 p24 Ag, HIV-1 and HIV-2 antibodies
Reactive result:
-Does not distinguish between Ag and Ab
-Preliminary positive
-Supplemental testing required

24. Advantages of HIV Algorithm
HIV-1/HIV-2 assays must easier to use
Timely results
Reduced number of indeterminate results

25. Disadvantages of HIV Algorithm
Cost of new HIV-1/2 Ag/Ab assays
NAAT testing for low volume of specimens

26. State Law
CCR 1230: HIV Screening Testing by Laboratories − Must use FDA approved test − Confirm all reactive or indeterminate HIV test results by the CDC confirmation protocol − Maintain a QA program that includes: Competency of testing personnel Assessment of test performance

27. Adoption in California
CCR does not allow the adoption of new algorithms until published in the MMWR
Delay of MMWR due to HIV 1 / 2 differentiation test (BioRad Multispot) not listed as a supplemental test in package insert.
Hope for MMWR by the end of the year. (HIV Diagnostics Conference, Dec 11 – 14, 2012, Atlanta, GA.)

28. Status of Recommendations
Clinical and Laboratory Standards Institute
Criteria for Laboratory Testing and Diagnosis of Human
Immunodeficiency virus Infection;
Approved guideline 2011
Special Edition of Journal of Clinical Virology
66532/52/supp/S1
CDC Recommendations Summer/Fall 2012
Will parallel CLSI document

29. Rapid HIV 1/2 Ag-Ab Test

30. Those Never Tested 1.2 million have HIV 240,000 unaware of HIV status
50,000 new HIV infections each year occur
from those not aware of HIV status
● At risk individuals would test more
frequently if convenient test available

31. Home Testing

32. Acknowledgements
Bernard M. Branson, M.D., Associate Director for Laboratory Diagnostics, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention Monica Parker, PhD, Laboratory Chief, Bloodborne Diseases, New York State Department of Health, Albany, NY Michele Owen, PhD, Laboratory Branch/Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA

33. Questions? Bea.Okeefe@cdph.ca.gov LFS Web site: