Investigation of the Increased Rate of False Positive Results Using an

Oral Mucosal Rapid HIV Test

Centers for Disease Control and Prevention

Minnesota Department of Health

New Jersey Department of Health & Senior Services

Wisconsin Division of Public Health

Background

• University of Minnesota demonstration project• Finger stick and oral mucosal transudate (OMT) rapid

HIV tests• Incidence of Type I, II discordant results• Factors associated with discordant results

• OMT test Clinical Laboratory Improvement Amendment (CLIA) waived

• OMT test was scheduled for launch end- August 2004

Preliminary Data

• July 2002 – April 14, 2004: – 2,022 individuals tested– 7 OMT false positives (0.35%)

• April 15, 2004 – July 22, 2004:– 266 individuals tested– 15 OMT false positives (5.6%)

• 5-20% false positive rates reported in community trials

Investigation

• Started with Epi Aid investigation on invitation of Minnesota Department of Health

• Developed into multi-state investigation• Key component is case control study

Objectives

• Determine rate of false positive OMT rapid HIV tests

• Determine factors associated with false positive OMT tests

• Host immunological factors• Medical conditions• Interfering substances

Sites and Duration

• New Jersey, Wisconsin, Minnesota

• New Jersey:– Robert Wood Johnson (New Brunswick)– Henry J. Austin (Trenton)– NJCRI– Bergen County– Atlantic City Health Department– East Orange Health Department

• 4 months

Study Population

• Cases (n=150):• 50 to be enrolled in NJ• Reactive OMT rapid test• Non-reactive finger-stick rapid test• Exclude HIV positive individuals after confirmatory HIV test

result

• Controls (n=450):• 150 to be enrolled in NJ• Non-reactive OMT rapid test• Non-reactive finger-stick rapid test• Exclude HIV positive individuals after confirmatory HIV test

result• Exclude temporally related controls after case confirmed to be

HIV positive

Eligibility Criteria

• 18 yrs or older• No previous HIV diagnosis• No history of antiretroviral therapy• No HIV vaccine

Methods

• Phase I• Conduct fingerstick and OMT rapid HIV tests• Administer questionnaire• Collect serum and OMT specimens• Perform HIV confirmatory testing on serum and OMT• Analyze test devices• Bank specimens for Phase II• If sufficient OMT false positives, continue study

Methods

• Phase II• Continue recruitment of cases and controls• Perform all other laboratory tests• Analyze data using multivariate logistic regression• Continue device analysis

Laboratory Tests

– Serum:– Hepatitis A, B, C– Rheumatoid factor– EBV– Quantitative HCG pregnancy test– ANA– RPR– Protein electrophoresis– Gel electrophoresis with immunofixation for Ig estimation– HSV I and II– CMV

– Oral fluid:– Confirmatory HIV EIA/WB– Immunoglobulin estimation- protein electrophoresis

Analysis of Test Devices

• Microscopy or other physical methods to characterize false positive results

• Ship devices to CDC

Step 1:Enrolling Study Participants

Enrolling a Case1. Administer written consent for rapid tests (stage 1)

2. Perform fingerstick and OMT rapid tests

3. Assess if potential case• Non-reactive fingerstick result• Reactive OMT result

4. Check for eligibility

5. Administer written consent (stage 2)

6. Administer questionnaire

7. Collect blood and OMT specimens

8. Ship specimens and devices to CDC

Enrolling a Control1. Administer written consent for rapid tests (stage 1)

2. Perform fingerstick and OMT rapid tests

3. Assess if potential control• Non-reactive fingerstick result• Non-reactive OMT result

4. Check for eligibility

5. Administer written consent (stage 2)

6. Administer questionnaire

7. Collect blood and OMT specimens

8. Ship specimens and devices to CDC

Clinic Flow

Case

Control # 1 Control # 2 Control # 3

Recruit CASE: Reactive OMTNon-reactive fingerstick

Recruit next 3 consecutive CONTROLS: Non-reactive OMTNon-reactive fingerstick

Step 2:Interview

Questionnaire• Hand-held devices• Enter

– subject ID, location, date and time– fingerstick and OMT device lot numbers– fingerstick and OMT test results

• Go through all questions• Confirm subject ID at end of interview

Step 3:Shipping Specimens and Devices

to CDC

Specimens and Devices• Specimens

– 37 mL venipuncture whole blood• 3 serum separator tubes: red top/tiger top (10 mL each)• 1 plasma preparation tube (PPT) or lavender top EDTA (7

mL)

– OMT• 2 Orasure OMT

• Devices– Rapid OMT and fingerstick for all cases and controls

Labels• Serum, plasma, OMT

– Subject ID label– Gender and CDC lab project number label

• Mp225• Fp225

– Seal lid with adhesive tape: must be watertight– Wrap each vial/tube in foam envelope

• Devices– Subject ID label– Place each OMT device in plastic ‘BIOHAZARD’ bag

Packaging Specimens• Plastic or metal containers

– Follow all instructions included – Label container with name, address and phone

number of shipper– Pad between vials with absorbent wrapping material– DO NOT place ice in this container

Specimen Submission Form

• Appendix E in protocol• One copy between container and shipping

box• Fax second copy to:

– Dollene Hemmerlein (770) 339-5915  – Krishna Jafa (404) 639-8640

Outer packaging• Bio-transporter box

– Follow all instructions included– Place copy of specimen submission form between

container and box (fax second copy)

Label the Shipment– ALL labels on same side, alongside each

other, clearly visible• Name, address and phone number of shipper• Diagnostic specimen UN 3373 label • Orientation label (which side is ‘Up’)• Address label: name, complete facility name,

shipping address, phone number • Label with ‘Person Responsible for Shipment’

and 24 h/7 d phone number (no pagers)

Shipping Options

• Preferred:– Same day, on ice– Serum: centrifuge, transfer into cryotubes – Plasma: centrifuge, transfer into cryotubes, DO NOT freeze – OMT

• If centrifuge not available– Same day, on ice– Serum (in red top tube)– Plasma (in lavender top tube), DO NOT freeze – OMT

• Ship all rapid test devices with specimens

Shipping• Fedex with CDC account number • Typed or computer generated• Sign form• Monday through Thursday• DO NOT ship on Friday

Ms. Dollene Hemmerlein/Project 225

CDC Serum Bank 602 Webb Gin House Rd.

Lawrenceville, Georgia 30045                   

Telephone: (770) 339-5917

Supplies From CDC

• Shipping containers and boxes• Labels:

– Fedex– Gender, project number (e.g. Mp225)

• If required:– Cold packs– Tubes and vials

Summary

• Perform fingerstick and OMT rapid tests• Recruit case and 3 consecutive controls• Administer questionnaire• Ship specimens and devices

Acknowledgments

Division of HIV/AIDS Prevention, CDCAtlanta,GA

Pragna Patel Patrick Sullivan

Bernard BransonKevin DelaneyDuncan MackellarSteven EthridgeJeffrey WienerAmy DrakeGlenn NakamuraTricia Hall

Minnesota Department of HealthMinneapolis, MN

Stephen Swanson Tracy Sides

Peter Carr

Hennepin County Health Dept.Minneapolis, MN

Deborah PersellMargaret Simpson

New Jersey Department of Health and Senior Services

Trenton, NJSindy M. PaulRose Marie MartinKen EarleyPhil BrucolariMaureen WolskiLorhetta NicholAyemaung MaungRhonda Williams

UMDNJ Robert Wood Johnson Medical SchoolEugene G. MartinEvan Cadoff

Wisconsin Division of Public HealthMadison, WI

Alexandra NewmanJim VergerontKathleen KrchnavekMatt MaxwellAmy DoczyMary Jo Hussey