National HIV and Retrovirology Laboratories

The Public Health Agencies of Canada's National HIV and Retrovirology Laboratories (NHRL) provide a comprehensive range of laboratory science services and expertise related to HIV and emerging retroviruses. Organizations that use these services include laboratories associated with provincial ministries of health, hospital and blood-screening laboratories, and HIV laboratories abroad. The NHRL's core activities are:

• Reference Services
• Quality Assurance
• Surveillance Outbreak Investigation
• Research
• International Activities

The NHRL is comprised of the following laboratories:

The National Laboratory for HIV Reference Services (NLHRS) provides HIV and HTLV (Human T-cell Leukemia Virus I/II) serology and molecular reference services in support of testing programs conducted by provincial ministries of health and the Canadian Blood Services. The laboratory also works closely with the Canadian Association of HIV Laboratory Specialist to ensure that HIV testing in Canada is among the best in the world. The NHLRS provides quality assurance programs to national and international laboratories for HIV viral load testing, and HIV antibody testing. The accuracy of the results submitted by each laboratory is determined with feedback provided to all participating laboratories. The NHLRS also provides expertise and guidance to international communities, assisting with the development and implementation of quality assurance programs in their own countries.

NLHRS is actively involved in the development and optimization of new and innovative technologies (HIV-2 viral load testing, HTLV quantitative testing, optimization and improvement of molecular techniques). It also provides surveillance support for a variety of National epidemiological studies.

The National Laboratory for HIV Genetics (NLHG) performs genetic analysis of HIV for a number of activities including the Canadian HIV/AIDS Strain and Drug Resistance Surveillance Program, (CHSDRSP). Through a collaboration between the NLHG, the Surveillance and Risk Assessment Division, and the provinces and territories, this program monitors and evaluates trends in HIV drug resistance and HIV subtype distribution. The CHSDRSP ensures the quality of HIV diagnostic testing, informs vaccine development, guides antiretroviral selection and facilitates our understanding of HIV transmission patterns.

Additional NHLG activities included administering a national HIV drug resistance quality assurance program, assisting in outbreak investigations with molecular epidemiology services, supporting drug resistance studies, and promoting technology development and transfer through international collaboration.

The NLHG also studies other retroviruses of potential public health significance. The NLHG has evaluated the potential risks associated with porcine endogenous retrovirus (PERV) transmission to possible xenotransplant recipients and continues to study simian foamy virus (SFV) as a marker for potential cross-species transmission of retroviruses from monkeys to humans.

The National Laboratory for HIV Immunology (NLHI) is the national resource centre for flow cytometry based diagnostics of cellular immunological diseases. All activities can be defined as service and method development oriented work in the field of infectious disease reduction and prevention.

Under the service category, the laboratory manages the nationwide CD4 T-cell enumeration external quality assessment programme (EQAP). This EQAP serves all members of the Canadian Clinical Trials Network engaged in drug and vaccines studies in the fight against HIV. Similar EQAP has been developed to support resource-poor countries administering antiretroviral drugs. This international program is called QASI and in addition to the Agency, receives financial support from the World Health Organization, the Centre for Disease Control and Prevention in the United States, the Clinton Foundation and some other agencies. This international initiative supports EQAP for CD4 T-cell counting in remote locations where no commercial EQAP is available.

As part of method research component, NLHI evaluates and develops various HIV surrogate markers and cellular-based assays to help establish early indicators of failure/restoration of the immune competency of individuals living with HIV. NLHI is committed to share knowledge by the providing of expert training and skills build workshops both at home and abroad.

The Viral Evolution and Molecular Epidemiology Unit (VEMEU)

The Viral Evolution and Molecular Epidemiology Unit is involved in several activities strategically positioned to reduce the impact of HIV. Studies include the use of dried blood spots (DBS) for HIV drug resistance genotyping; studying the prevention of mother-to-child transmission of HIV in resource-limited settings, the Polaris seroconversion study and the evaluation of a novel SIV vaccine candidate deleted of all accessory genes. Seroconversion is the progression after initial infection from HIV-negative status to HIV-positive status.

 

Reference Services Activities:

• HIV serological and molecular testing of challenging samples for provincial laboratories and the Canadian Blood Services;
• Ability to test a variety of challenging samples (tissue, cadaveric, dried blood specimens, etc.);
• Provides advice and expertise to Canadian laboratories performing HIV/HTLV testing;
• Development of new technologies
• Evaluation of diagnostics test kits, and;
• Training (national and international).

Quality Assurance Activities:

• HIV serology Quality Assurance Program;
• HIV viral load Quality Assurance Program;
• HIV Drug Resistance Quality Assurance Program;
• Lymphocyte Enumeration (CD4 cell counting)Quality Assurance Program;
• Assisting in the development of international quality assurance programs.

Surveillance and Outbreak Investigations:
(in collaboration with national epidemiological studies)

• I-Track, M-Track: HIV and Hepatitis C testing from dried blood spots for
• Street Youth Program: HIV, HTLV, Hepatitis C and HSV antibody testing
• Canadian HIV Strain and Drug Resistance Surveillance Program (CHSDRSP):
  • Diagnosis of recent infection (detuned testing)
  • Strain Determination
  • Drug Resistance Genotyping
  • Molecular Epidemiology
• Emerging Retrovirus Surveillance Program
• Nunavut HTLV study: outbreak investigation

Research / International Activities

1. Evaluation and promotion of affordable and portable CD4 T-cell Enumeration
   

   There is a need to develop more cost-effective CD4 T-cell counting technologies for resource-limited regions. One challenge is the lack of affordable monitoring systems that function at remote locations in Africa and Asia. Recent advances in light emitting diode (LED) technology are leading the way in developing cost-effective and portable fluorescence microscopes.

2. Point of Care Flow Cytometry
   

   Until recently, compact user-friendly flow cytometry was unavailable. NHRL scientists, in cooperation with industry, is developing a battery-powered affordable flow cytometer that requires little in the way of training to perform CD4 T-cell counting at point of patient care at remote locations.

3. Drug Resistance Surveillance
   

   Methods for HIV drug resistance (HIVDR) surveillance are needed as part of the on-going search for effective antiretroviral treatment. This has led the NHRL to evaluate the use of dried blood spots (DBS) for HIVDR genotyping. Studies in Mexico suggest that results obtained from DBS are equivalent to those from plasma. This data therefore indicates that DBS are useful for HIVDR surveillance, especially in countries where specimens might be exposed to severe conditions and delays in processing.

4. Knowledge Transfer

   While laboratories may already exist, guidance may be needed for testing algorithms and their application to HIV surveillance. This sometimes requires the exchange of scientific personnel and knowledge. Disruptions such as military conflict can diminish both infrastructure and testing capacity that may have taken years to develop. Laboratories often require assistance and training to rebuild their capacities.

5. Linking Facilities

   The Worldwide Analysis of resistance Transmission over time of Chronically and acute infected HIV patients (WATCH) program seeks to analyse HIV-1 reverse transcriptase and protease gene sequences from patients from all over the world that have had no previous treatment. The result will be a database on the worldwide transmission of drug-resistant HIV-1. WATCH is also working to build a global collaborative network of researchers involved in HIV resistance, integrating efforts when needed. The National Laboratory for HIV Genetics is one of NHRL's contributors to the WATCH program.

6. Training and Technical Assistance
   
   NHRL's National HIV Immunology Laboratory offers skills-building workshops and other means to support members of the Canadian HIV Clinical Trial Network to assure consistent quality CD4 T-cell counting across Canada. NHRL is now playing a key international role abroad in skills-building workshops and biotechnology capacity transfer seminars. They are focussed on: (1) technology transfer of T-cell enumeration at a technical level, (2) capacity-building at senior laboratory manager level to establish quality management practices, and (3) introduce the essential elements required to run a national external quality assessment programme (EQAP) that is linked to an international EQAP called QASI. NHRL staff give lectures, technology transfer sessions, and skills-building workshops in Ottawa and around the world in English, French and Chinese to support effective evaluation and monitoring of HIV positive individuals.

7. Alternative Technology
   
   Through research initiatives with the NHRL, the Howard Hospital in rural Zimbabwe has been building HIV/AIDS infrastructure. The Howard Hospital makes use of DBS for diagnosing infant HIV infections and monitoring viral load. The hospital uses the ExaVir Load to monitor the viral loads of Mother-to-Child transmission study participants, as well as treated patients of the Tariro AIDS clinic. NHRL study data demonstrates that the ExaVir Load assay may in fact offer a cost-effective and more technically friendly than commercial assays.
   
   
   • Quality Assessment in Developing Countries
     The International program for Quality Assessment & Standardization for Immunological (QASI) measures relevant to HIV/AIDS provides a CD4 T-cell quality assessment program. The objective is to assure the quality of CD4 T-cell testing in countries where such services are unavailable. For many resource-limited countries, this is the only way to assess HIV disease state and determine what antiretroviral treatment is needed. There are now over 300 participating laboratories in over 50 countries, located mostly on the Southern Hemisphere. QASI is the world's largest EQAP for CD4 T-cell immunophenotyping that covers Africa, Asia and the Americas. It was developed and is operated by NHRL's National HIV Immunology Laboratory (NLHI). QASI periodically ships stabilized whole blood samples that are deigned to emulate stressed-challenge specimens. All aspects of communication between QASI and the participating laboratories can be handled via the Lympho Site Web interface, a special software the NLHI has developed.
     
     
   • CD4 T-cell Enumeration in Remote Locations
     To monitor immunodeficiency levels in HIV infected individuals, CD4 T-cell enumeration remains the most effective method. WHO supports bringing national laboratory performances to internationally acceptable levels. This is achieved through integration of national efforts and the introduction of reproducible T-cell counting protocols as part of an external quality assessment program (EQAP). The domestic experience revealed that frequency of participation in an EQAP has a desirable impact on the performance of the laboratories. The use of the Lympho Site Web interface further reduces the response time required to generate performance reports, therefore extending the time for remedial action at the participants' end.

International Partners

NHRL's international collaboration and involvement through:

• WHO
• UNAIDS
• Canadian International Development Agency (CIDA)
• Centers for Disease Control (CDC)
• Health Canada
• Fogarty International Center
• International Union of Immunological Societies (IUIS)
• Pan American Health Organization (PAHO)
• American Public Health Laboratories (APHL)
• Doctors without Borders (Médecins Sans Frontières)
• Global AIDS Program (GAP)
• Clinton Foundation
  

Publications

• The most recent report on HIV-1 Strain and Primary Drug Resistance in Canada can be found through the following link:
  http://www.phac-aspc.gc.ca/publicat/epiu-aepi/index.html
  http://www.phac-aspc.gc.ca/id-mi/sfv-vss-20041021ra-eng.php

Links

Contact us at:

Office of the Director
National HIV and Retrovirology Laboratories
Room 3252
100 Eglantine Driveway
Tunney's Pasture
Ottawa, ON K1A 0K9
Phone 613-946-0841
Fax 613-957-7258