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Sustaining an Effective Response to Acute HIV Infection Among Gay Men
BC Gay Men’s Health Summit – November 3, 2011Mark Gilbert
BC Centre for Disease Control
Contributors
Michael Kwag Malcolm Steinberg Darrel Cook Mel Krajden
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CIHR Acute HIV Study Team and Collaborators
HIV Emerging Team
National HIV and Retroviral LaboratoriesJames Brooks
National Lab for HIV GeneticsPaul Sandstrom Terry Trussler, Rick Marchand, Olivier Ferlatte
North Carolina HIV/STD PreventionPeter Leone
Josephine McIntoshMathematics Department
Daniel Coombs
STI/HIV Prevention & ControlMichael Rekart, Mark Gilbert, Malcolm
Steinberg, Michael Kwag, Bill Coleman, Gina Ogilvie, Melanie Achen,
Glenn Doupe, Daphne Spencer, Cory Genereaux, Daniel Grace, Sarah Chown,
Robin ParryMathematical Modeling
Babak Pourbohloul, Jennifer Lindquist, Flavia Moser
Laboratory ServicesMel Krajden, Darrel Cook, Wendy Mei
EpidemiologyDavid Patrick
Benedikt Fisher
Elgin LimJody Jollimore, Hans BosgoedWayne Robert
Captain Snowden
Richard Rothenberg
Recruitment Sites12th Avenue, Bute Street, Spectrum Health, 3 Bridges, Dr Richard Taylor, Cook Street, HIM SHC
Presentation Outline
Background (Acute HIV, Window Periods) Overview of CIHR study & social marketing
campaigns Description of the impact of introducing testing for
acute HIV infection (pooled NAAT testing) Review of current policy options & next steps
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Why is acute HIV important? HIV prevention
– High viral load = high probability of transmission– Earlier diagnosis & potential for behaviour change– Active sexual networks
(Brenner JID 2007; Fraser CROI 2006; Galvin Nature Rev Micro 2004; Hayes JID 2005)
Appearance of markers of HIV infection
(BCCDC 2010)
Window period – “standard testing”
3 - 4 weeks
Window period – pooled NAAT
10-12 days
Not easy to understand, or explain!
Window periods HIV test options Acute HIV and why important
Ramifications?– Delays in testing (wait 3-6 months to test)– Not taking advantage of current tests
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December 2009 - Feb 2010
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August 2011 to present
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Relevant CIHR study objectives To diagnose acutely infected gay, bisexual and other MSM using
innovative laboratory testing methods (NAAT and 4th generation EIA tests)
To promote HIV testing as a first response to risk events through community based social marketing initiatives
Methods – HIV positive cohort Mixed-methods (quant/qual), longitudinal cohort study Recruitment: April 2009-December 2012 Eligibility:
Gay or MSM, 19 or older Acute or recent HIV diagnosis
Study sites: 7 clinics in Vancouver– Gay men as clients; history of frequent HIV diagnosis in gay men
Intervention: Enhanced HIV testing protocol (NAAT) Enhanced support: Professional and Peer-based counseling
Current participants: 23 (9 acute; 14 recent)
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For this analysis
Used PHSA laboratory testing data to describe the impact of introducing pooled NAAT testing at the CIHR study sites
Compared pre- and post-pooling periods
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New positive HIV tests, Men 19+ years CIHR study sites
0
5
10
15
20
25
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Other
Recent
Acute
Pooled NAAT
Summary of HIV test results from AHI CIHR project sites (Q1 2007 – Q2 2011)
Pre-Pooling(Q1 2007 – Q4 2008)
Post-Pooling**(Q1 2009 – Q2 2011)
% Change
Test Volume* (specimens)
14,178(~525 per month)
16,075(~600 per month)
13% increase
Test Volume* (individuals)
10,284 11,056 8% increase
All New positive HIV Cases
173 155 10% decrease
Acute HIV Cases 15 34 127% increase
Recent HIV Cases 36 40 11% increase
For the acute HIV cases identified post-pooling, 14 (41%) would have been missed if only the standard HIV test algorithm had been used.
* Negative Point of Care tests not included. **HIM clinic added Sept 2010
Factors explaining increase?
Introduction of pooled NAAT testing Impact of social marketing campaigns Increased testing volume Other?
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Conclusion?
Introducing Pooled NAAT testing is effective! – Diagnoses made that would otherwise be missed– Greater opportunities for prevention of HIV transmission
Valuable prevention tool for gay men
What now? The study ends December 2012…
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Acute HIV “Buzz”
Potential benefit recognized from outset by community and public health partners
These results have been discussed within STOP Considered a success
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Option1 : Sustain or expand pooled NAAT…
Problem: $$$ Not cost-effective to implement province-wide Looking into:
– Sustaining beyond 2012 at the study sites– Expansion to select HIV testing sites with high diagnosis
rates
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… and/or Option 2: 4th generation screening tests
2 - 3 weeks
… and/or Option 2: 4th generation screening tests
Implemented in Quebec Cheaper test, could implement across province Reduces window period of “standard” test, would detect
more acute HIV infections than 3rd gen EIA However, would miss many acute HIV infections as well
– We looked to see how well two types of 4th gen EIA tests did at detecting HIV in the 14 men with acute HIV infection diagnosed through pooled NAAT: approximately 40-70% were missed.
Gay men are more likely to test during the acute phase of HIV infection
What next? Merits to both options (our preference: both) Preparing appropriate policy documents & business
case for decision-makers Conducting further head-to-head comparison of
pooled NAAT and 4th gen screening tests, to better understand impact (2012)
Publication of findings & knowledge translation
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What do you think?
Contact Info: – Mark Gilbert, Co-Principal Investigator
• [email protected] – Michael Kwag, Research Project Manager
• [email protected]• 778-886-7781