1 / 17

HIV Testing and Diagnosis

HIV Testing and Diagnosis. Dr. Kate Templeton SPAIIN –Stirling 2011. Overview. HIV Infection Tests used in diagnostic labs How to access them Challenges HIV prevention Non –conformity to existing strategies. Anti-HIV antibody. Immunological fitness. Anti-HIV antibody.

viveca
Download Presentation

HIV Testing and Diagnosis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HIV Testing and Diagnosis Dr. Kate Templeton SPAIIN –Stirling 2011

  2. Overview • HIV Infection • Tests used in diagnostic labs • How to access them • Challenges • HIV prevention • Non –conformity to existing strategies

  3. Anti-HIV antibody Immunological fitness Anti-HIV antibody Historic Major Diagnostic Opportunities 0 1 5-30+ +1 Years (average) Opportunities to Identify HIV Infections Asymptomatic phase Symptomatic phase AIDS Seroconversion illness Death

  4. List of tests • HIV screening test • 4th generation • EIA format • Includes Antigen as well as Antibody • On large automated machines • HIV confirmation • Blot • 2nd EIA • HIV RNA – viral load • HIV proviral DNA – used to detect HIV in children <18 months old

  5. RNA ‘Quantity’ DNA avidity Ag IgG3 IgM IgG viral spread 0 1 2 3 4 5 6 12 24 Weeks post-infection Understanding markers during an infection….HIV local viral growth

  6. Murex HIV Ag/Ab combionation Vitros ECi anti-HIV 1/2 Murex HIV 1/2 VK84/85 Vironostika HIV Uniform II Ag/Ab Ortho Ab-capt. ELISA Architect HIV Ag/Ab Combo Biotest HIV 1/2 recombinant Innotest HIV-1/-2 Access HIV 1/2 NEW GENSCREEN PLUS HIV Ag-Ab Enzygnost HIV 1/2 plus Biotest Anti-HIV TETRA ELISA 5 0 10 15 20 Murex ICE HIV 1+2 days Murex HIV 1.2.0 GE94/95 VIDAS HIV DUO Earliest HIV detection Abbott 3rd gen Plus Clonesystems Detect-HIV v1 Earliest anti-HIV detection Enzygnost HIV Integral Vironostika HIV Uniform II plus O IMx HIV1/2 III plus Pasteur Genscreen Version 2 AxSYM HIV 1/2 gO Understanding Applied to Serological Detection of Primary HIV Infection(35 Seroconversion Panels)

  7. HIV testing • Antenatal booking • HIV – 4th gen • HBsAg • Syphilis IgG • Rubella IgG • Any HIV screen • 4th gen HIV assay • Caution – maternal HIV antibody can be present for 15-24 months

  8. Screening EIA A1 + A1- report negative Assay 2- 2nd EIA A1+ A2- Repeat A1 and A2 A1+ A2 + A1+ A2+ A1+ A2- A1- A2- report negative Assay 3- blot A1+ A2+ A3+ A1+ A2+ A3- A1+ A2- A3+ A1+ A2- A3- Low risk: negative report positive High risk consider indeterminate WHO HIV Strategy III • Low prevalence • asymptomatic

  9. Mother to child transmission

  10. Antenatal screening roll-out ZDV monotherapy Parry, bioMérieux Symposium, Oct 2006 Pat Tookey, Institute of Child Health

  11. IgG Anti-HIV reactivity HIV RNA IgG Anti-HIV titre HIV proviral DNA Reactivity‘/ Quantity’ P24 Ag IgA/M Anti- HIV IgA/M Anti- HIV 0 1 2 3 4 5 6 ….12 …..18 Months post-partum HIV markers in Perinatally INFECTED child

  12. HIV testing to exclude HIV infection • BHIVA/CHIVA guidelines • EDTA blood- baby • At birth within 1 day • 6 weeks ( 2-weeks after stopping Rx) • 3 months • Need 2 HIV proviral DNA while off therapy • Antibody • EDTA blood – Mother • HIV genetically diverse – check assay integrity against Mothers specific virus. • HIV viral load is optional – can give false positives/ or more sensitive • Following exposure in genital tract

  13. Summary of testing

  14. HIV proviral DNA testing • EDTA samples should be sent need prior telephone notification • Specialist Virology Centre • Department of Laboratory Medicine • Royal Infirmary of Edinburgh • 51, Little France Crescent • Edinburgh • EH16 4SA • BBV team can be contacted on 0131 242 7129 • Duty Virologist can be contacted on 0131 242 6086 • or0131 536 1000, bleep 5981

  15. Laboratory processing • EDTA blood should be <24 hours old by time in Edinburgh lab – preferably sooner. • Keep at room temperature • Can arrive: • Monday –Friday 0900 -2000 • Saturday – 0900-1200 • Current turnaround time is 7-10 days • Any positive results are phoned to referring clinician

  16. Final point • HIV protocol for access to HIV testing to exclude infection in babies should be available via SPAIIN website.

More Related