INSTI HIV1

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INSTI HIV-1 HIV-2 Rapid Antibody Test Fast
Accurate Reliable
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Laboratory Testing vs Rapid Testing

• Laboratory Testing
• Full clinical infrastructure
• Accredited quality system
• Professional laboratory staff
• Slow
• Complex (requires specialist staff and equipment)
• Loss of follow up
• Large overheads

• Rapid POC Testing
• Access to clinics as needed
• CE approved
• Professional laboratory staff
• Fast results while waiting
• Simple no specialist staff, equipment or
  storage conditions
• Immediate follow up
• No additional costs or overheads

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Rapid HIV POC Test

• Laboratory Use
• Use serum or plasma
• equivalent to screen test
• Point of Care Use
• Use whole blood
• near-patient testing
• office/on-site testing
• equivalent to screen testing

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What To Look For In An Ideal Point of Care HIV
Test?

• Convenient specimen easy collection and no
  preparation necessary
• All materials in kit / no equipment
• Stable at wide range of environmental conditions
• Long shelf-life
• Simple / foolproof procedure and simple and
  legible instructions
• Easily read visual result
• Rapid result under 5 minutes
• Accurate
• Inexpensive

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INSTI - The Product

• INSTI HIV-1 and HIV-2
• Rapid Antibody Test
• In vitro membrane-based qualitative test for the
  detection of antibodies to Human Immunodeficiency
  Viruses Types 1 and 2 (collectively referred to
  as HIV-1/2) in human whole blood, serum or
  plasma.
• Immediate, Results in 60 seconds
• Accurate 99.96 - large scale Canadian clinical
  trials
• True human IgG control
• Simple to use
• No additional materials required

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INSTI Components

• Sealed foil pouch
• containing
• Alcohol Swab
• Sterile Lancet
• Pipette
• Test Device
• Solution 1 Buffer
• Solution 2 Developer
• Solution 3 Clarifier
• Instructions for use

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INSTI Features

• 99.96 accurate
• Result in 60 seconds
• Use 50µl of EDTA whole blood, finger stick blood,
  serum or plasma
• Proven early antibody detection
• Built-in True Human IgG Control
• Easy to understand instructions
• No timing required
• No refrigeration required
• Minimum order 10 tests
• 12 months shelf life
• Cost 7 per test

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Interpretation Non-Reactive Tests

• NEGATIVE
• One blue dot, clearly discernable above any
  background tint on the membrane.
• This is the Procedural Control Spot shows test
  has been performed correctly. The control is
  located towards the top of the read frame,
  furthest from the plastic tab on the Membrane
  Unit.
• No reaction should be visible at the test spot,
  located below the control.
• This result indicates antibodies to HIV-1/HIV-2
  were not detected.

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Interpretation Reactive Tests

• POSITIVE
• Two blue dots discernable above any background
  tint indicate presence of HIV-1/HIV-2 antibodies.
• One dot may be darker than the other.
• A sample giving this pattern is considered a
  preliminary positive.
• Following a reactive rapid test result, a venous
  blood sample must be drawn for confirmatory
  testing.

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Interpretation Indeterminate Tests

• There is no dot on the membrane
• The test dot appears without the control dot

• Uniform tint across the membrane
• Only blue specks appear on membrane

INVALID tests with fingerstick blood samples in
POC settings should be repeated with a fresh
sample using a new membrane unit, kit components
and support materials.
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Interpretation Borderline

• The test is INDETERMINATE if a faint background
  ring appears on the test area.
• Following an indeterminate test result, a venous
  blood sample must be drawn in an EDTA collection
  tube (for whole blood or plasma) or red-top tube
  (for serum), and forwarded to a laboratory for
  HIV confirmatory testing.

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Rapid Test Controls

• BE AWARE!
• procedure control, as indicated by some rapid
  test devices may only control for the flow of
  fluids through the device, NOT if proper sample
  and/or amount is used.
• These devices will produce a valid result even
  with water
• True IgG-capture controls will work only if human
  blood is present in the test sample, in
  sufficient amounts

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The Procedure Control in Some Lateral Flow
Devices
blood
membrane
This format will produce a valid control line
with any fluid as a sample, even water
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Parallel vs. Serial Testing

• Parallel testing

• Serial testing

Positive result
Test 2
Source WHO Rapid HIV Tests guidelines for use
in resource constrained settings, 2004
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Quick Comparison Chart
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Sensitivity, Specificity and Predictive Values

• Sensitivity the ability of an assay under
  evaluation to correctly identify specimens that
  contain antibody. a/(ac)
• Specificity the ability of the assay under
  evaluation to correctly identify specimens that
  do not contain antibody to HIV. d/(bd)
• Confidence limits the 95 confidence limits are
  a means of determining whether observed
  differences in sensitivity or specificity between
  assays are significant or not

Source WHO report on simple/rapid tests, 2002,
www.who.int/eht/
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Sensitivity, Specificity and Predictive Values

• Positive Predictive Value
• The probability that when the test is reactive,
  the specimen does contain antibody to HIV.
• It can be calculated in two ways Using the
  simple formula which will give an approximate
  value a/(ab), or the more accurate formula
  which factors in the prevalence of HIV in the
  population.
• In general, the higher the prevalence, the
  greater the probability that a person testing
  positive is truly infected, ie., higher PPV, less
  false positives.

• Negative Predictive Value
• The probability that when the test is negative, a
  specimen does not have antibody to HIV.
• Also calculated using a simple formula d/(cd)
  or the more accurate formula which factors in the
  prevalence of HIV in the population.
• NPV decreases as prevalence increases, ie
  greater chance that negatives are false. This
  only becomes apparent at prevalence of 80 or
  higher.

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INSTI Canadian Trial -Background Information

• All diagnostic and blood screening HIV testing
  devices in Canada are regulated through the
  Bureau of Medical Devices, Health Canada. Insti
  is the first rapid HIV testing device approved
  for use in point-of-care POC) settings in Canada.
• Objective
• To assess the performance of the INSTI Rapid
  HIV-1/HIV-2 Antibody Test Kit through a large
  scale prospective clinical trial, conducted in
  accordance with the Medical Devices Regulations,
  Health Canada, for approval for use in POC,
  clinical and laboratory settings.

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INSTI Canadian Trial -Background Information

• Study Design
• Intended Patient/Sample Population
• A prospective, cross-sectional, voluntary-testing
  population of 2,500 consenting patients of
  unknown HIV status, from 3 provinces (BC,
  Alberta, Ontario), representing all risk levels,
  plus 1,000 combined archived and prospective
  samples from patients with confirmed HIV-1
  infection (commencing Sept, 2003).
• Up to 300 world-wide confirmed HIV-2 frozen,
  archived plasma/serum samples.
• 25 commercial seroconversion panels, to measure
  early antibody detection.
• Study Protocol
• Patients were enrolled in the study through
  participating POC sites including Medical, STD,
  Family Planning, Anonymous Testing and
  hospital-based Immunodeficiency Clinics in
  Vancouver, Calgary and Toronto. Patients from the
  Vidus (Vancouver injection drug user study) and
  Vanguard (Vancouver gay mens study) cohorts were
  also included.
• Finger-stick whole blood was collected and tested
  with the INSTI kit at the POC sites. Matching
  venous blood was also collected in EDTA tubes
  from all patients and forwarded to the Provincial
  Public Health Laboratories (PHL). A subset of
  matching red-top blood samples (for serum) was
  collected in selected clinics.
• At the PHL, INSTI testing was carried out on
  matching EDTA blood as well as plasma and serum,
  within 48 hours of collection. Gold standard
  serology testing by the PHL test of record
  (Abbott AxSym MEIA HIV 1/2 GO in all PHL sites)
  was conducted on serum and/or plasma, with
  discordant and/or indeterminate results resolved
  via supplemental EIA, Western Blot, and p24Ag as
  necessary.
• Three production lots of INSTI were tested.
• All staff performing INSTI were trained and
  validated by Biolytical prior to testing patient
  samples.
• Patients were not provided with results of the
  INSTI rapid test.

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INSTI Canadian Trial - Results
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Counselling Issues

• What are your experiences in counselling patients
  pre- and post-testing?
• New strategy for HIV testing
• 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

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Q A Session