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HIV Rapid Tests Procurement for VCT Service Delivery Dvora Joseph by dffhrtcv3

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									    HIV Rapid Tests 101:
Procurement for VCT Service
          Delivery

Dvora Joseph, HIV/AIDS Service Delivery Manager
                 PSI/AIDSMark

       Presentation for PSI Procurement
                  July 8, 2005
Conventional approach to HIV Testing:
               ELISA
 • Enzyme-linked immunoabsorbent assay (ELISA)
 • Requires machine to measure color change in test wells
   (spectrophotometer)
 • Designed for batch testing (>100 specimens at a time) -
   can be automated
 • Most useful for surveillance and centralized blood
   transfusion testing
 • Centralized QA/QC: Done at National and Regional
   Laboratories - easy to control
 • Obtain informed consent and prepare client for HIV
   testing
     Limitations of ELISA for VCT
• Not flexible (need minimum no. samples filled for
  maximum efficiency)
• Requires specialized equipment (automatic pipettes,
  incubators, washers, test tubes, etc.)
• Requires highly skilled & trained technicians to perform
  and read results
• Machine requires maintenance
• Requires venous blood sample and central laboratory
• Results can not usually be provided on same-day (1-2
  week delay often involved)
   Rationale for Development of
   Rapid HIV Testing Technology
  The rationale for HIV diagnostic testing has changed:
  Beginning of Epidemic: Clinical confirmation of
  suspected HIV disease
  Present Stage of Epidemic: Prevention & care
  potential of knowing one’s HIV status (VCT setting)

Advent of rapid testing technology has simplified HIV
  testing allowing to move-on-site and away from
  centralized laboratories
   Characteristics of HIV Rapid Tests
• Based on four immunologic principles: particle
  agglutination, immunodot, immunofiltration and
  immunochromatography
• Positive test kit result indicated by clumping, a spot, a
  dot or line (visual to naked eye)
• Most rapid tests detect antibodies to both HIV-1 and
  HIV-2
    Advantages of Rapid Tests compared
                 to ELISA

• More flexible (efficient for 1 to multiple tests at a time)
• Requires minimal equipment and reagents
• Does not require highly trained or skilled staff
• On-site clinic testing can be performed easily
• Very easy to interpret test results (naked eye)
• Samples can obtained less invasively (finger-prick) -
  safer to lab technician
• Same-day screening and confirmation of results
  (available <30 min.)
       Advantages of ‘Same Day’ Rapid
               Test Results
     Lower client travel time and expenses
     Less anxiety during waiting period
     More likely to get same counselor for both pre- and
     post-test counseling
     Client post-test adherence increases dramatically
     (99+% compared to 60-80%)
     Client VCT intake increases dramatically (500%  in
     Malawi VCT centers, 1999-2000)*
     Facilitates expansion of VCT services in resource-
     constrained settings (remote areas, mobile clinics, etc.)

*Msowoya K, Marum E et al. Rapid testing and same day counseling results in huge increase
in demand for for VCT in Malawi. International AIDS Conference Abstract Durban, 2000.
      HIV Rapid Test Algorithm
      Development (ANNEXE C)
  Use multiple (up to 3) rapid test kits in parallel or in
  series to maximize positive and negative prediction
  values (required for diagnostic purposes)
Parallel testing: Clients are tested using two test
  simultaneously (in parallel) - if tests discordant (<1%
  occurrence) than a 3rd type of rapid test is used
  (“tiebreaker”)
Serial testing: Clients test with one rapid test. If result is
  positive, a 2nd different rapid test used. Discordant
  test results are further tested with 3rd different type of
  rapid test (tests done in series)
       Advantages of Parallel (vs. Serial)
             Testing Algorithm*
   Minimize the risk of false negative test result
   Clients perceive that two tests are better than one -
   reduces client ‘shopping around’ phenomenon
   Can do two rapid tests with one finger-stick
       reduces potential stigma that might result if patient called
       back a second time)
       Shorter clinic waiting times resulting from simultaneous
       testing
Disadvantage: Parallel testing more expensive b/c using at
  least two tests for each client


*Adapted from: FHI, 2001. Issues in diagnostics for VCT - ‘Focus on’ series.
       HIV Rapid Test Algorithm
         Development (cont.)
First ‘screening’ rapid test should be as sensitive as
possible (minimize false negatives)
Follow-up ‘confirmatory’ tests need to be highly specific
(minimize false positives)
Use ‘Level 1 complexity’ test kits* - require little to no
laboratory experience or additional equipment and only
finger-prick blood
Selected test kits should be recommended by
UNAIDS/WHO (see ‘Report of Operational
Characteristics of Commercially Available HIV Tests’)

      *e.g., Determine, Uni-Gold, HemaStrip and Oraquick
  General Outline for Country Evaluation
      of HIV Testing Technologies
    Phase I: Retrospective evaluation of the sensitivity and
      specificity of selected tests at the national reference
      laboratory
    Phase II: Prospective evaluation of the selected tests at the
      regional laboratories
    Phase III: Prospective evaluation of selected tests at
      settings where they will most likely be used

    NOTE: Outline should be adapted upon for specific country
      evaluations

*UNAIDS/WHO/CDC. 2001. Guidelines for Using HIV Testing Technologies in Surveillance.
      VCT Clinic Rapid Test QA/QC*
Ongoing External Quality Control
Proficiency Testing
• Every month, random 5-10% of total sample load (ideally
  including +ve and -ve test results) sent to reference
  laboratory for ELISA testing cross-checking
• All rapid test kit algorithm ‘indeterminate’ results
  confirmed with ELISA testing before results provided to
  client
            Critical Issues for Rapid Test
                        QA/QC*

     •   Use of test kits that have not expired
     •   Training with the technology being used
     •   Adherence to manufacturer’s instructions
     •   Correct interpretation and transcription of
         results by person reading results




*UNAIDS/WHO/CDC. 2001. Guidelines for Using HIV Testing Technologies in Surveillance.
       PSI Procurement of RTKs:
•   Approved List of       Product         Source                        Manufacturer
                                          Country
    Testing Kit        Bioline         South Korea Standard Diagnostics
    Products and       Bionor          Norway           Bionor A/S
                       Capillus        Ireland          Trinity Biotech*
    Manufacturers as   Determine       Japan            Abbott Laboratories*
    of July 6, 2005    DoubleCheck     Israel           Orgenics
                       First Response  India            Premier Medical Corporation
•   12 Highlighted     Genie II        France           BioRad
    manufacturers      Hema-Strip      Singapore        Saliva Diagnostic Systems, Ltd.*
                       HIVSav 1&2      Israel           Sayvon Diagnostics Ltd.
    make tests that    Immunocomb      Israel           Orgenics
    PSI countries      Instant Screen  Germany          GAIFAR GmbH
    procure from       InstantCHEK     USA              EY Laboratories
                       OraQuick        Singapore        OraSure Technologies
    PSI/W              SeroCard        Ireland          Trinity Biotech*
                       Sero-Strip      Israel           Saliva Diagnostic Systems, Ltd.*
                       Stat-Pack       USA              ChemBio Diagnostics, Inc.
                       SureCheck HIV USA                ChemBio Diagnostics, Inc.
                       Unigold         Ireland          Trinity Biotech
                       * Parent Company is a United States based firm
    PSI PROCUREMENT COUNTRIES AND TEST
              MANUFACTURERS
•   BENIN- ABBOTT, TRINITY (UNIGOLD) AND ORGENICS
•   GUYANA- ABBOTT, TRINITY, CHEMBIO, SALIVA
•   HONDURAS- ORASURE
•   COTE D’IVOIRE- ABBOTT, PREMIER MEDICAL CORPORATION,
    TRINITY BIO
•   KOSOVO- ABBOTT
•   LESOTHO- ABBOTT, ORGENICS, TRINITY BIO-TECH
•   MALI- ABBOTT, ORASURE, SALIVA DIAGNOSTICS AND CHEMBIO
•   MOZAMBIQUE- ABBOTT, TRINITY
•   TOGO- ABBOTT AND ORGENICS
•   UGANDA- ABBOTT, CARRAMORE, CHEMBIO AND TRINITY BIO-TECH
•   WCA AMBASSADOR FUND- ABBOTT, ORGENICS
•   WEST AFRICA REGION- ABBOTT, ORGENICS, TRINITY
•   ZAMBIA- ABBOTT, BIORAD, TRINITY

•   12/13 use Abbott Determine RTKs, all other VCT countries do as well
         Questions?


      See H Drive: AIDSMark:
Read Only: VCT: RTK and Lab for more
            information….

								
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