Primary HIV Drug Resistance Surveillance in Canada

1
Primary HIV Drug Resistance Surveillance in
Canada

• Surveillance and Risk Assessment Division
• National HIV and Retrovirology Laboratories,
• Public Health Agency of Canada
• and
• Participating Provinces and Territories

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Canadian HIV SDR Program Partners

• Pubic Health Agency
• Of Canada (PHAC) British Columbia Manitoba
• Chris Archibald Michael Rekart Magdy Dawood
• Marianna Ofner Mel Krajden Valerie Mann
• Jocelyne Galloway Mark Gilbert Greg Hammond
  (ret)
• James Brooks
• Paul Sandstrom Saskatchewan Alberta
• Harriet Merks Huiming Yang Ameeta Singh
• Richard Pilon Fred Sidaway Jutta Preiksaitis
• Mark Vanderkloot
• Ping Yan Ontario Nova Scotia
• Carol Swantee Maureen Baikie
• Robert Remis Robert Strang

3

• Field Surveillance Officers, PHAC
• Elsie Wong (British Columbia)
• Sabrina Plitt (Alberta)
• Erin Laing (Saskatchewan)
• Michelyn Wood (Manitoba)
• Claudia Rank (Ontario) Tracey MacDonald (Nova
  Scotia)
• HIV Surveillance Section, PHAC
• Jenni Vick
• Kristina Lalonde
• Stéphane Racette

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Highly Active Antiretroviral Therapy for HIV

• Introduction of highly active antiretroviral
  therapy (HAART) for HIV changed the HIV landscape
• Morbidity and mortality have decreased
• The widespread use of HAART, along with
  continuing HIV incidence, results in the
  potential for transmission of drug-resistant
  viruses
• Drug resistance in untreated individuals is
  primary drug resistance and is due to
  transmission of DR strain from treated individuals

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Secondary versus Primary (Transmitted) Drug
Resistance
Failing Therapy
Secondary DR
Rx
Rx
HIV person not on treatment
Primary DR
WT
Wild Type Virus
Drug Resistant Virus
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Goals of the Canadian HIV Strain and Drug
Resistance Program

• Improve HIV diagnostics and screening strategies
  for circulating strains
• Inform vaccine development
• Assess genetic markers for anti-retroviral drug
  resistance among newly diagnosed, treatment-naïve
  individuals
• Assess HIV transmission patterns

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Sampling methods

• Population-based study comprising all individuals
  newly diagnosed with HIV for whom left-over
  diagnostic serum samples are available
• No subjects are directly recruited
• Only first-time positive, treatment-naïve
  individuals are included

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Data Collection and Transfer
National HIV Laboratories
Serum specimens
Epidemiological data
subtype data
Provincial Partners
PHAC
primary DR mutations
detuned assay data
laboratory results plus epidemiological data
Surveillance Division
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http//www.phac-aspc.gc.ca/publicat/hiv1-vih1-05/i
ndex.html
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Results
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HIV Drug Resistance in Canada 1996-2005
(N2703)
Wild Type 90.6
Drug Resistance 9.4
(1 case since 1996)
Results of 4 western provinces
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Mutations Associated with DR
NRTI
PI
NNRTI
13
Characteristics of individuals with primary drug
resistant HIV-1
14
Characteristics of individuals with primary drug
resistant HIV-1
15
Primary HIV DR in Canada, by drug class and
year
16
Trends in primary DR over time
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Discussion

• 9.4 of newly diagnosed HIV cases have primary DR
  and no indication that this is changing recently
• trends are seen for certain drug classes
• virtually no triple-drug resistance in Canada
  (only 1 case recorded)
• Primary DR most common in
• subtype B infection may indicate differential
  access to treatment
• recently infected cases may indicate not all
  mutations are persistent

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Public Health Implications

• Data on prevalence of primary drug resistance can
  be used to develop population recommendations for
  initial treatment (especially for pregnant women
  and situations of post-exposure prophylaxis)
• Extent of transmitted drug-resistance can serve
  as an indicator to help evaluate the
  effectiveness of prevention programs

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Future directions

• Continue to improve representativeness of program
  in Canada
• Expand analysis of data
• - examine mutation distributions by HIV-1 subtype
  
• - use the detuned testing data to monitor trends
  and associated characteristics of the new
  diagnoses that are recent infections
• Encourage public health use of data
• Maintain and expand collaboration with
  international partners