Title: Performance%20of%20Bio-Rad%20Genetic%20Systems%20HIV-1/HIV-2%20Plus%20O%20EIA%20Followed%20by%20Multispot%20or%20OraQuick%20Advance%20in%20a%20Dual%20Immunoassay%20HIV%20Testing%20Strategy
1Performance of Bio-Rad Genetic Systems
HIV-1/HIV-2 Plus O EIA Followed by Multispot or
OraQuick Advance in a Dual Immunoassay HIV
Testing Strategy
- Laura Wesolowski, PhD
- S. Michele Owen, PhD
- Debra Candal, BS
- Susan Phillips, BS
- Steve Ethridge, BS, MT (ASCP)
- Duncan MacKellar (MA, MPH)
Diagnostic Applications Team, Behavioral and
Clinical Surveillance Branch, Centers for Disease
Control and Prevention
2Objectives
- To assess the sensitivity and specificity of a
dual immunoassay testing strategy using Bio-Rad
HIV-1/HIV-2 Plus O EIA (A1) followed by Multispot
HIV-1/HIV-2 rapid test (A2) for HIV-1 diagnosis - To describe the concordance of A2 test
(Multispot) when run in duplicate - To assess the sensitivity of a dual immunoassay
testing strategy using Bio-Rad EIA (A1) and
OraQuick Advance (A2) rapid test for HIV-1
diagnosis
3Background
- Lack of performance data for EIA followed by
rapid test - Concern about similarity of antigens in EIAs and
rapid tests on market - may contribute to dual false positives
- Bio-Rad EIA
- 3rd generation EIA (detects IgG and IgM)
- Serum or plasma
- Sensitivity 100 (99.84-100)
- Specificity 99.89 (99.83-99.96)
4Background Multispot
- Serum or plasma
- Sensitivity
- Serum and plasma
- 100 (99.94-100)
- Specificity
- Serum
- 99.93 (99.79-100)
- Plasma
- 99.91 (99.77-100)
5Background OraQuick Advance
- Whole blood or plasma
- Sensitivity
- Whole blood
- 99.6 (98.5 - 99.9)
- Plasma
- 99.6 (98.9-99.9)
- Specificity
- Whole blood
- 100 (99.7-100)
- Plasma
- 99.9 (99.6-99.9)
-
6Methods HIV-1 uninfected specimens
- HIV-uninfected specimens plasma samples from
uninfected blood donors - EIA negative (Abbott HIV AB HIV-1/HIV-2 (rDNA))
- Pooled HIV-1 PCR-negative (Roche Ampliscreen)
- Uninfected specimens tested with Bio-Rad EIA and
Multispot (in duplicate) at CDC. Not tested with
OraQuick yet.
7Methods HIV-1 infected specimens
- HIV-1 infected specimens Serum Western blot
positive specimens from CDCs Validating
Supplemental Testing to Confirm Preliminary
Positive Rapid HIV Tests - CDC IRB Approved Feb. 2006
- Enrollment began March to June 2006
- Enrollees from 6 study sites
- AIDS Research Consortium of Atlanta, GA
- Denver Metro Health (STD) clinic
- Philadelphia FIGHT, Jonathan Lax HIV Clinic
- Howard Brown Health Center, Chicago, Gay
Lesbian Health Clinic - Louisville Hospital, Louisville, KY, WINGS STD
Clinic - University of MD Baltimore, Evelyn Jordan Center
(HIV Clinic) - Reference laboratory University of MD
8Methods HIV-1 infected specimens
- Inclusion criteria
- Previously diagnosed with HIV infection
- No antiretrovirals within 3 months
- Not pregnant
- 18 - 55 years
- Understand English
- Infected specimens tested at UMD (Bio-Rad EIA)
and CDC (Multispot in duplicate) - OraQuick Advance conducted at study site using
whole blood (not in duplicate)
9Methods Outcomes
- Specificity and sensitivity for Bio-Rad EIA (A1)
followed by Multispot (A2) individually and
together in dual test strategy - Concordance of Multispot results run in duplicate
- Sensitivity for Bio-Rad EIA (A1) followed by
OraQuick Advance (A2) individually and together
in dual test strategy
SpecificityTrue negative/(true negative false
positive) SensitivityTrue positive/(true
positive false negative)
10Results Specificity Bio-Rad EIA and Multispot
- Among 302 HIV-uninfected persons
- 4 false positive on Bio-Rad EIA
(specificity298/30298.7) - 7 false positive on Multispot (specificity295/302
97.7) - 0 false positive on both Bio-Rad EIA and
Multispot -
11Strategy 3. HIV-1/2 dual immunoassay for 4
initially false positive on Bio-Rad EIA (truly
uninfected)
A1 BioRad EIA
A1 ()
A1 (-)
Negative for HIV-1 and HIV-2 antibodies
A1 (- -)
Repeat A1 in duplicate
A2 Multispot in duplicate
A2 (- -)
A1 ( or -)
A2 ( or -)
Inconclusive for HIV antibodies request plasma
redraw for NAAT Requires medical follow-up for
further evaluation and testing
Presumptive positive for HIV-1 or HIV-2
antibodies requires medical follow-up for
further evaluation and testing
HIV-2 Testing Strategy 5, if applicable
Must be a different EIA, CIA, or non-waived
rapid test depending on laboratory setting (for
A2 only) If window period infection is
suspected based on risk assessment or discordant
testing, refer to Acute HIV Infection Testing,
Strategy 4
12Results Specificity Bio-Rad EIA and Multispot
- Strategy specificity excluding those with
inconclusive results300/300100 - 2 uninfected persons eventually get correct
results, but in the interim will be told that
their results are inconclusive and have to wait
for correct results after NAAT testing
13Results Sensitivity Bio-Rad EIA and Multispot
- Among 1065 HIV-infected persons
- 0 false negative on Bio-Rad EIA
(sensitivity1065/1065100) - 1 false negative on Multispot (sensitivity1064/10
6599.9) - 0 false negative on both Bio-Rad EIA and
Multispot
14Strategy 3. HIV-1/2 dual immunoassay for 1
person false negative on Multispot (truly
infected)
A1 BioRad EIA
A1 ()
A1 (-)
Negative for HIV-1 and HIV-2 antibodies
A1 (- -)
Repeat A1 in duplicate
A2 Multispot in duplicate
A2 (- -)
A1 ( or -)
A2 ( or -)
Inconclusive for HIV antibodies request plasma
redraw for NAAT Requires medical follow-up for
further evaluation and testing
Presumptive positive for HIV-1 or HIV-2
antibodies requires medical follow-up for
further evaluation and testing
HIV-2 Testing Strategy 5, if applicable
Must be a different EIA, CIA, or non-waived
rapid test depending on laboratory setting (for
A2 only) If window period infection is
suspected based on risk assessment or discordant
testing, refer to Acute HIV Infection Testing,
Strategy 4
15Results Sensitivity Bio-Rad EIA and Multispot
- Strategy sensitivity excluding those with
inconclusive results1064/1064100 - 1 HIV-infected person likely have inconclusive
results and would have to await NAAT results
16Results Multispot duplicates
- All Multispots same result on duplicate as when
initially run (i.e. non-reactive on both test
runs or reactive on both test runs) - Testing in duplicate did not provide any
additional information on infection status for
those with false positive or false negative
results
17Results Sensitivity Bio-Rad EIA and OraQuick
- Among 1065 HIV-infected persons
- 0 false negative on Bio-Rad EIA
(sensitivity1065/1065100) - 0 false negative on OraQuick (whole blood)
(sensitivity1065/1065100) - 0 false negative on both Bio-Rad EIA and OraQuick
- Strategy sensitivity1065/1065100
18Conclusions
- Dual test strategy using Bio-Rad EIA and
Multispot has high sensitivity and specificity.
However, some persons would receive inconclusive
results and require additional testing to get
correct result. - Conducting the secondary screening test in
duplicate does not appear to be beneficial. - Dual test strategy using Bio-Rad EIA and OraQuick
has high sensitivity, though specificity should
be evaluated.
19Next steps
- Continue testing samples with Bio-Rad EIA,
Multispot and OraQuick - Obtain challenge specimens (false EIA positive,
NAAT negative) to challenge dual immunoassay
strategy
20Acknowledgements
- PIs staff from 6 study sites
- University of MD Laboratory of Viral Diagnostics
- MDC Associates, Joanne Lebrun
- CDC
- Bernard Branson
- Maxia Dong
- Tim Granade
- Dollene Hemmerlein
- Sheryl Lyss