HIV TESTING PROCIDURES presented by Dr Munawar SACP

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Rapid HIV Testing::

Rapid HIV Testing: Presented by: Dr. M. Munawar Khan BCC COORDINATOR SACP

Rapid HIV Testing: 2005 Update:

Rapid HIV Testing: 2005 Update Presentation of Bernard M. Branson, M.D. Associate Director for Laboratory Diagnostics Division of HIV/AIDS Prevention Presented by: Dr. M. Munawar Khan BCC COORDINATOR SACP

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Number HIV infected 850,000 - 950,000 Number unaware of their HIV infection 180,000 - 280,000 Awareness of Serostatus among Persons with HIV, United States

Advancing HIV Prevention: New Strategies for a Changing Epidemic:

Four priorities: Make voluntary HIV testing a routine part of medical care Implement new models for diagnosing HIV infections outside medical settings Prevent new infections by working with persons diagnosed with HIV and their partners Further decrease perinatal HIV transmission Advancing HIV Prevention: New Strategies for a Changing Epidemic MMWR April 18, 2003

Four FDA-approved Rapid HIV Tests:

Four FDA-approved Rapid HIV Tests Sensitivity (95% C.I.) Specificity (95% C.I.) OraQuick Advance - whole blood - oral fluid - plasma 99.6 (98.5 - 99.9) 99.3 (98.4 - 99.7) 99.6 (98.5 - 99.9) 100 (99.7-100) 99.8 (99.6 – 99.9) 99.9 (99.6 – 99.9) Uni-Gold Recombigen - whole blood - serum/plasma 100 (99.5 – 100) 100 (99.5 – 100) 99.7 (99.0 – 100) 99.8 (99.3 – 100)

Four FDA-approved Rapid HIV Tests:

Four FDA-approved Rapid HIV Tests Sensitivity (95% C.I.) Specificity (95% C.I.) Reveal G2 - serum - plasma 99.8 (99.2 – 100) 99.8 (99.0 – 100) 99.1 (98.8 – 99.4) 98.6 (98.4 – 98.8) Multispot - serum/plasma - HIV-2 100 (99.9 – 100) 100 (99.7 – 100) 99.9 (99.8 – 100)

OraQuick Advance HIV-1/2:

OraQuick Advance HIV-1/2 CLIA-waived for finger stick, whole blood, oral fluid; moderate complexity with plasma Store at room temperature Screens for HIV-1 and 2 Results in 20 minutes

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Obtain finger stick specimen…

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Insert loop into vial and stir

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Collect oral fluid specimens by swabbing gums with test device. Gloves optional; waste not biohazardous

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Insert device; test develops in 20 minutes

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Positive Negative Reactive Control Positive HIV-1/2 Read results in 20 – 40 minutes

Uni-Gold Recombigen:

Uni-Gold Recombigen CLIA-waived for finger stick, whole blood; moderate complexity with serum, plasma Store at room temperature Screens for HIV-1 Results in 10 minutes

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Add 1 drop specimen to well

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Add 4 drops of wash solution

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Read results in 10 -12 minutes Positive Negative

Reveal G2:

Reveal G2 CLIA moderate complexity with serum, plasma Reconstitute and refrigerate reagents Screens for HIV-1 Perform test in 5 minutes

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Centrifuge to obtain serum or plasma

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Add buffer to reconstitute conjugate. (Sufficient for 15 tests; Refrigerate to store)

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Add 3 drops buffer to moisten membrane

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

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Add 4 drops of Colorimetric Detection Agent

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Add 3 drops of buffer to wash

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Read results immediately Reactive Negative

Multispot HIV-1/HIV-2:

Multispot HIV-1/HIV-2 CLIA moderate complexity with serum, plasma Refrigerate reagents Distinguishes HIV-1 from HIV-2 Perform test in 15 minutes

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Dilution of plasma or serum

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Remove and discard pre-filter

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Several timed reagent & wash steps

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Negative HIV-1 & HIV-2 Positive Peptide HIV-2 Recombinant HIV-1 Peptide HIV-1 Reactive Control

Remember the tradeoffs…:

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.

Interpreting Rapid Test Results:

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

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

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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%

Positive Predictive Value of a Single Test Depends on Specificity & Varies with Prevalence:

Positive Predictive Value of a Single Test Depends on Specificity & Varies with Prevalence Test Specificity HIV Prevalence Predictive Value, Positive Test 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% OraQuick Single EIA Reveal 99.9% 99.8% 99.1% 97% 95% 87% 77% 63% 50% 25% Uni-Gold 99.7%

Routine HIV Screening for Emergency Department Patients:

Routine HIV Screening for Emergency Department Patients OraQuick testing since October 2002 60% accept HIV testing 98% receive test results 2.5% new HIV positive 80% entered HIV care 4 new demonstration projects (Wisconsin, Massachusetts, Los Angeles, New York) Cook County Hospital, Chicago

Characteristics Rapid Test Positive Patients:

Characteristics Rapid Test Positive Patients

HIV Screening in Acute Care Settings:

HIV Screening in Acute Care Settings Cook County ED, Chicago 2.5% Grady ED, Atlanta 2.7% Johns Hopkins ED, Baltimore 3.2% Massachusetts (4 hospitals) 2.0% HIV testing sites 1.2% New HIV+

HIV Screening with OraQuick in Labor and Delivery: the MIRIAD Study:

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 4894 women screened 34 (0.7%) new HIV infections identified 4 false positive OraQuick tests, no false negatives 11 false-positive EIAs: 5 p24 only, 6 WB negative Positive Predictive value: OraQuick 90%; EIA 76% Bulterys et al, JAMA July 2004

Turnaround Times for Rapid Test Results, Point-of-Care vs Lab Testing:

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

OraQuick Outreach Testing for High-risk Persons: El Paso :

OraQuick Outreach Testing for High-risk Persons: El Paso On-site testing at community sites: Old Plantation night club and mobile van Individual counseling and testing El Paso Gay Community Center and Centro de Salud Familiar la Fe

OraQuick Fingerstick Results: N = 1275:

OraQuick Fingerstick Results: N = 1275 Preliminary positive 18 (1.4%) True positives 17 (1.3%) False Positives 1 (0.07%) Specificity 1256/1257 (99.9%) Positive Predictive Value 17/18 (94%) All clients received their test results

OraQuick Outreach to High-risk Persons of Color :

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

Outreach Testing Sites:

Outreach Testing Sites Chemical Dependency Programs Homeless shelters Sex worker support program Drop-in center for gay youth Teen clinic Gay bars Sex offender groups “Johns” programs Half-way houses Health fairs Strip club workers African-born groups Drug court support groups

OraQuick Fingerstick Results: N = 1021:

OraQuick Fingerstick Results: 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%)

Results:

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.

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CDC’s OraQuick Procurement & Distribution 527,775 test kits shipped in 2003 and 2004 137 health depts and CBOs in 36 states Utilization September 2003 – September 2004: 173,003 persons tested 2,741 (1.6%) HIV positive 17,266 devices used for training 25,926 devices use to run external controls

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02 03 02 03 02 03 02 03 Changes in HIV Testing at Same Sites After Rapid Testing Introduced

Changes in Positive Tests at Same Sites After Rapid Testing Introduced:

Changes in Positive Tests at Same Sites After Rapid Testing Introduced 02 03 02 03 02 03 02 03

Results of Confirmatory Testing:

Results of Confirmatory Testing MMWR March 19, 2004

Results of Confirmatory Testing:

Results of Confirmatory Testing Initial EIA or confirmatory test negative Some labs did only EIA HIV-positive on follow-up specimen 5 patients:

Results of Confirmatory Testing:

Results of Confirmatory Testing Initial confirmatory test indeterminate Early infection, evolving Western blot HIV-positive on follow-up specimen 4 patients:

Results of Confirmatory Testing:

Results of Confirmatory Testing Initial and follow-up tests negative False-positive OraQuick rapid test 4 patients:

Results of Confirmatory Testing:

Results of Confirmatory Testing Unsuccessful follow-up HIV status unconfirmed 8 patients:

Confirmatory Testing:

Confirmatory Testing Confirmatory test essential (not just EIA!) For Western blot: Venipuncture for whole blood Oral fluid specimen Follow-up testing of persons with negative or indeterminate Western blot results after 4 weeks

Additional Resources:

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

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