1 / 9

Proposed Testing Strategies for Laboratory-Based HIV Testing

Proposed Testing Strategies for Laboratory-Based HIV Testing. 2007 HIV Diagnostic Testing Conference Atlanta, GA December 5, 2007 Berry Bennett, MPH Fl. Bureau of Laboratories Special thanks to Bernard Branson, MD, Co-Chair CDC. Why do we need new laboratory-based HIV diagnostic strategies?.

alexpeters
Télécharger la présentation

Proposed Testing Strategies for Laboratory-Based HIV Testing

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. Proposed Testing Strategies for Laboratory-Based HIV Testing 2007 HIV Diagnostic Testing Conference Atlanta, GA December 5, 2007Berry Bennett, MPHFl. Bureau of Laboratories Special thanks to Bernard Branson, MD, Co-ChairCDC

  2. Why do we need new laboratory-based HIV diagnostic strategies? Introduction of new, more sensitive antibody assays (3rd, 4th, etc. generation) Apparent discordance between newer screening assays and traditional supplemental assays. Introduction of nucleic acid amplification-based diagnostic assays Need to refer client/patients to medical care and further evaluation in a timely manner Manufacturer’s decision on assay(s) continued production Focus on Acute Infection Testing Need for better HIV-2 confirmation Other…..

  3. Algorithm 1. HIV-1 EIA/WB/NAAT A1 EIA (HIV-1) Proposed Testing Strategies for Laboratory HIV Testing Facilities A1(+) A1 (-) Repeat A1 (in duplicate) A1(- -) Negative for HIV-1 antibodies† B2 Individual HIV-1 NAAT (option for initial plasma submissions) A1 (++ or - +) OR B1 HIV-1 WB or HIV-1 IFA Negative* Positive** Positive Negative Indeterminate Positive for HIV-1 antibodies and HIV-1 RNA Positive for HIV-1 antibodies Negative for HIV-1 antibodies† Inconclusive for HIV-1 antibodies; request redraw in 2-4 weeks; requires medical follow-up for further evaluation and testing †∞ * HIV-1 RNA not detected, however, a WB or IFA should be performed to confirm the absence of HIV-1 antibodies. Medical follow-up for further evaluation and testing may be required. ** It may be necessary to repeat a positive NAAT for confirmation † If window period infection is suspected, refer to Acute HIV Infection Testing, Algorithm 4 ∞ If HIV-2 infection is suspected, refer to HIV-2 Testing, Algorithm 5

  4. Algorithm 2. HIV-1/2 Immunoassay-WB/IFA/NAAT A1 HIV- 1/2 immunoassay (e.g. EIA or CIA) Proposed Testing Strategies for Laboratory HIV Testing Facilities A1 (-) A1(+) Negative for HIV-1 antibodies and HIV-2† Repeat A1(in duplicate) A1 (- -) A1 (++ or - +) B2 Individual HIV-1 NAAT (option for initial plasma submissions) OR B1 HIV-1 WB or HIV-1 IFA Negative* Positive** Positive Negative Indeterminate Positive for HIV-1 antibodies and HIV-1 RNA Inconclusive for HIV-1 antibodies; request redraw in 2-4 weeks; requires medical follow-up for further evaluation and testing † Positive for HIV-1 antibodies Negative for HIV-1 antibodies† HIV-2 Testing; Algorithm 5; if applicable * HIV-1 RNA not detected, however, a WB or IFA should be performed to confirm the absence of HIV-1 antibodies. Medical follow-up for further evaluation and testing may be required. ** It may be necessary to repeat a positive NAAT for confirmation † If window period infection is suspected, refer to Acute HIV Infection Testing, Algorithm 4

  5. A1 (++ or +-) A1 (-) Algorithm 3. HIV-1/2 Dual Immunoassay A1HIV-1/2 Immunoassay (e.g. EIA or CIA) Proposed Testing Strategies for Laboratory HIV Testing Facilities A1 (+) A1 (-) Negative for HIV-1 and HIV-2 antibodies† A1 (- -) Repeat A1 in duplicate A2HIV-1/2 immunoassay* in duplicate A2(- -) A1(++ or + -) A2 (++ or + -) Inconclusive for HIV antibodies; request plasma redrawfor NAAT† Requires medical follow-up for further evaluation and testing Presumptive positive for HIV-1 or HIV-2 antibodies; requires medical follow-up for further evaluation and testing HIV-2 Testing; Algorithm 5, if applicable *Must be a different EIA, CIA, or non-waived rapid test depending on laboratory setting (for A2 only) † If window period infection is suspected based on risk assessment or discordant testing, refer to Acute HIV Infection Testing, Algorithm 4

  6. Algorithm 4. Acute HIV Infection Testing Non-reactive HIV-1 or HIV-1/2 Immunoassay (e.g. EIA, CIA) Proposed Testing Strategies for Laboratory HIV Testing Facilities OR Pooled HIV-1 NAAT* Individual HIV-1 NAAT Pool (+) (Optional: repeat pooled NAAT) Pool (-) NAAT(-) NAAT(+)** Intermediate and/or individual NAAT Negative for HIV-1 RNA NAAT(+)** NAAT(-) Positive for HIV-1 RNA, likely acute HIV-1 infection; requires medical follow-up to document seroconversion; further evaluation and testing recommended *User validation may be required for pooled testing (pool size to be determined by user) ** It may be necessary to repeat a positive NAAT for confirmation

  7. Algorithm 5. HIV-2 Testing Reactive HIV-1/HIV-2 Immunoassay with indications for HIV-2 (e.g. EIA, CIA) Proposed Testing Strategies for Laboratory HIV Testing Facilities OR C1 HIV-1/HIV-2 discriminatory assay C2 HIV-2 EIA C2 (+)* C2 (-) HIV-1 (-) HIV-2 (+) HIV-1 (+) HIV-2 (+) HIV-1 (-) HIV-2 (-) HIV-1 (+) HIV-2 (-) Negative for HIV-2 antibodies; for HIV-1 refer to originating algorithm Presumptive positive for HIV-2 antibodies Positive for HIV antibodies; need follow-up specimen to differentiate HIV-1 or HIV-2 ** Negative for HIV-2 antibodies; for HIV-1 refer to originating algorithm Negative for HIV-2 antibodies; for HIV-1 refer to originating algorithm Supplemental testing for HIV-2‡ *If HIV-2 EIA is reactive, specimen should preferably be tested on HIV-1/HIV-2 discriminatory or supplemental assay for further clarification. Alternatively, the specimen can be sent to an appropriate public health laboratory with HIV-2 supplemental testing capabilities. **Dilution testing may be required to differentiate between the strains, refer to package insert of the assay. ‡ Refer to appropriate public health or reference laboratory with HIV-2 supplemental testing capabilities. Because low viral loads are common with HIV-2 infection, testing plasma specimens for HIV-2 RNA is not reliable.

  8. Berry Bennett Robert Bormisa Bernard Branson Michael Busch Sheldon Campbell Elliot Cowan David Cross Kevin Delaney Steven Ethridge Richard Hodinka Marcia Kalish Sally Liska Brian Louie Steve McDougal Duncan Mackellar Joanne Mei William Meyer Robert Myers Robert O’Connell Michele Owen Mark Pandori Pragna Patel Sheila Peel Michael Pentella Liisa Randall Mark Rayfield Natalie Rice Travis Sanchez Susan Stramer Anthony Tran Barbara Werner Thanks to the Laboratory Workgroup Members

  9. With special thanks to … • Steve Ethridge, Laura Wesolowski and Amanda Smith, CDC • Anthony Tran and Natalie Rice, APHL • APHL/CDC Steering Committee

More Related