New tools for diagnosis and surveillance

Transcription

1 New tools for diagnosis and surveillance Beth A Skaggs, PhD Laboratory Advisor, Division of Global HIV/AIDS CDC-Mozambique AIDS MEDICINES AND DIAGNOSTICS (AMDS) ANNUAL STAKEHOLDERS AND PARTNERS MEETING 7 8 May 2013 Starling Hotel, Geneva, Switzerland

2 Dual HIV Syphilis Rapid Test Limited Antigen Avidity HIV Incidence Test Low Cost HIV Drug Resistance Assay

3 HIV-Syphilis Dual Path Platform Rapid Diagnostic Test Mr. Javan Esfandiari Chembio Diagnostic Systems, Medford, NY 2012 HIV Diagnostics Conference, Atlanta, GA

4 Dual Path Platform Addition of a recombinant treponemal antigen to the ChemBio HIV1/2 rapid test Seeking FDA approval Evaluated in CDC lab with good performance (B. Parekh, personal communication)

5 Sample Type N DPP HIV Syphilis Assay Syph Trep (-) Syph Trep (+) Syph Trep EIA Syph RPR Overall Calculations Blood ND ND Syph Trep Specificity= 97% Serum Plasma % CI; % Total N/A N/A Source: Esfandiari J Abstract, 2012 HIV Diagnostics Conference, Atlanta, GA

6 Sample Type N DPP HIV Syphilis Assay HIV1/2 (-) HIV 1/2 (+) HIV 1/2 EIA - + DPP test specificity Blood % % Serum % % Plasma % % Total % % HIV 1/2 CI

7 DPP HIV Syphilis Line N # Positive Sensitivity 95% CI HIV % % Syphilis Trep % % *Compared to ELISA followed by RPR confirmation

8 Development of a Limiting Antigen Avidity EIA to Estimate HIV-1 Incidence Bharat S. Parekh, PhD International Laboratory Branch Division of Global HIV/AIDS Centers for Disease Control and Prevention, Atlanta, GA

9 Tracking the leading edge of the epidemic Monitoring impact of prevention efforts Acute infection based on p24 RNA detection BED-Capture EIA initially developed and commercialized (Calypte Biomedical Corp, Oregon) Mean duration of recency 162 days New and improved assays based on antibody avidity Mean duration of recency 141 days

10 2-well avidity assay to calculate Avidity Index (AI) Singe-well limiting antigen avidity assay (LAg-avidity) LAg-avidity in lateral flow, rapid test format (preliminary stages of development) Specimens include- serum, plasma or finger prick in case of RT Use of recombinant gp41 antigen reduces impact of HIV subtype variation

11 Courtesy of B. Parekh

12 Courtesy of B. Parekh

13 Courtesy of B. Parekh

14 Cohort Amsterdam & Trinidad N. of Subjects (number of specimens) HIV-1 Subtypes Mean Recency Period (95% CI) in days 32 (170) B 132 ( ) Ethiopia 23 (143) C 139 ( ) Kenya 34 (80) A, D 143 ( ) All 89 (393) A, B, C, and D 141 ( ) Source: Parekh BS et al AIDS Res Hum Retroviruses 27:

15 Frequency of False Recent Classification (%) Cohort BED-CEIA LAg-Avidity EIA US, AIDS (n=261) 11 (4.2%) 0 (0%) Thailand, AIDS + TB (n=128) Cote d Ivoire, AIDS + TB (n=99) 1 (0.8%) 0 (0%) 2 (2%) 1 (1%) OVERALL (n=488) 14 (2.9%) 1 (0.2%) Source: Duong YT et al Plos One 7:1-9.

16 Chunfu Yang, DVM, PhD International Laboratory Branch Division of Global HIV/AIDS Centers for Disease Control and Prevention, Atlanta, GA

17 Sensitive for multiple HIV-1 subtypes and recombinants Accessible costs Simple specimen collection methods No cold chain requirements for sample shipment

18 ViroSeq HIV-1 (Abbott) TRUGENE HIV-1 (Siemens) approved for HIV-1 subtype B instrument specific expensive specimen: plasma (VL > 1000 copies/ml)

19 Source: Zhou et al. PLoS One. 2011; 6(11): e28184

20 100 Frozen plasma Frozen DBS DBS at Ambient T 2-wk % 98.1% 93.2% 90 P>0.05 P> N=103, median VL=4.76, range log 10 ) Fisher s exact test

21 N = 663 A1 B C D F G H 01_AE 02_AG 03_AB 06_cpx 07_BC 08_BC 09_cpx 10_CD 13_cpx UC URF

22 24 countries: 14 Africa, 5 Latin America, 3 Asia and 2 North America

23 Timepoint N Previous ART CD4 cells/ml Baseline VL # with VL>150 copies/ml # genotyped # with any resistance mutations Baseline 603 (57.2% female) 9* , /575 with VL results 23 (4%) 12 months after ART initiation 503 (436 alive on ART and 67 defaulters) N/A N/A N/A 35/395 with HIV RNA determinati ons (8.8%) 35/35 with VL results 24 (6%) Source: Wadonda-Kabondo et al Clin Infect Dis. 53:S

24 CDC HIV-dB supports for global HIV genotyping surveillance

25 Innovative and accessible HIV diagnostic tools are making important contributions to our knowledge of the HIV epidemic Mulitiplex rapid tests can be useful tools for diagnosis in RSL and can simplify supply chain, training, quality assurance and burden on health care workers HIV Incidence assays appropriate for multiple HIV-1 subtypes can help guide HIV transmission prevention and control efforts Affordable approaches to monitoring HIV DR can be added on to periodic population or sentinel HIV surveys to provide essential data on drivers of HIV DR

26 Beth Skaggs