An STBBI Testing Update and the Quest for the 300

Transcription

1 An STBBI Testing Update and the Quest for the 300 Jared Bullard MD FRCPC Paediatric Infectious Diseases & Medical Microbiology Associate Medical Director Cadham Provincial Laboratory WRHA STBBI Conference March 13, 2013

2 Conflict of Interest Disclosure Honoraria from Janssen and Merck for Manitoba HIV Program Continuing Medical Education

3 Objectives 1. Briefly review the common technologies used in STBBI testing 2. Review the unique trends of STBBI testing observed in Manitoba 3. Discuss the optimal approach for HIV testing in Manitoba

4 Serology 101 Antibody generated to pathogen Two main classes used in diagnosis: IgM (typically seen between 7-10 days postexposure) IgG (typically rises between 3-6 weeks) IgM used to determine acute infection IgG used to determine immune status BUT also can indicate infection if 4-fold rise in titre

5 Limitations of Serology False positives and false negatives: Immunocompromised Impact of early treatment Cross-reaction with similar pathogens Infection or immunization? Prolonged time to diagnosis

6 Molecular diagnostics Polymerase chain reaction (PCR) Nucleic acid amplification tests (NAATs) Nucleic acid sequence based amplification (NASBA)

7 Molecular diagnostics Advantages: Very sensitive and specific Rapid turnaround time (TAT) Large volume testing Disadvantages: Higher costs Limited to only what you look for Contamination Does not distinguish living from dead pathogen

8 STBBI Testing NAAT: Chlamydia trachomatis, Gonorrhea Serology: Hepatitis B Hepatitis C HIV Syphilis

9 From the Ontario Burden of Infectious Diseases Study, December 2010

10 What do you think is the STBBI with the highest years of life lost (YLL)? 1 1. Hepatitis C (7729) 2. Hepatitis B (6698) 3. Human papillomavirus (6167) 4. HIV (4929) 5. Chlamydia trachomatis (28) 6. Neisseria gonorrhea (27) 7. Syphilis (0) 1. From the Ontario Burden of Infectious Diseases Study, December 2010

11 From the Ontario Burden of Infectious Diseases Study, December 2010

12 Total number of tests STBBI tests performed in Manitoba in Ct HBV HCV GC HIV Syphilis

13 Most common STBBIs by positive tests at Cadham Provincial Laboratory Ct 2. Hepatitis B 3. Hepatitis C 4. GC 5. HIV 6. Syphilis

14 Positive tests per 10,000 STBBI positive test rates in Manitoba in Ct HBV HCV GC HIV Syphilis

15 Percentage of tests positive Percentage of positive STBBI tests in Manitoba in Ct HBV HCV GC HIV Syphilis Percentage of tests positive

16 STBBI test / 1000 population STBBI testing by RHA in Manitoba Ct GC HIV HBV HCV Syphilis - Regional Health Authority (RHA)

17 Canadian HIV Data 64,800 HIV infections in Canada from 1985 to Canadian children; most by mother-to-childtransmission (MTCT) Aboriginals account for 23% of new infections Approximately 15% of HIV-exposed infants Aboriginal 25% unaware of their HIV-positive status Manitoba has approximately 1200 known HIVpositive patients

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19 Number of Tests Number of HIV screening tests performed in Manitoba from 2000 to Number of HIV Screening Tests Year of test

20 STI test per 100 population Comparison of testing for Chlamydia/Gonorrhea and HIV by RHA in Manitoba in Ct/GC NAAT HIV EIA tests Regional Health Authority (RHA)

21 GC/Ct and HIV Tests/1000 Comparison of testing for Chlamydia/Gonorrhea and HIV by RHA in Manitoba in Ct GC HIV Regional Health Authority (RHA)

22 Test volume per 100 population Comparison of testing for Chlamydia/Gonorrhea and HIV by Age in Manitoba in HIV EIA test GC/Ct NAAT < Age (years)

23 STBBI test per 1000 Comparison of testing for Chlamydia/Gonorrhea and HIV by Age in Manitoba in GC/Ct HIV < Total Age Groups (Years)

24 Number of unique individuals tested for HIV in Manitoba from 2009 to 2011 Ct NAATs: 130,504 unique PHINS 10.9% of Manitoba population tested for Ct HIV EIAs: 96,693 unique PHINS 8.05% of Manitoba population tested for HIV 34,200 individuals at risk for HIV not tested

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26 Current HIV screening guidelines CDC (2006): Opt-out screening All people 13 to 64 years regardless of risk Repeated at least annually if considered at risk Repeat screening if presenting with STI complaints Screening not required if <1 HIV Dx per 1000 tested Adopted by the WHO in 2007 Canadian STI Guidelines (PHAC 2008): Screening based on risk-factors Informed consent required with pre and pos-test counselling

27 New Guidelines PHAC Guidelines currently being revised Manitoba STBBI Strategy being reworked

28 Point of care testing (POCT)

29 Why the push for HIV POCT in Manitoba? Assurance of linkage to care: Know from Manitoba HIV Program that there is 100% linkage to care Reach high risk populations: Currently under-testing for HIV (approximately 50% of GC/Ct rates) Saskatchewan HIV/GC+Ct testing rates in 2012 >95% BC HIV/GC+Ct testing rates ~80% Empower more individuals to test for HIV: HIV testing available across the province already

30 Why the push for HIV POCT in Manitoba? Treatment as Prevention Reduction of community VL to disrupt transmission Must first Dx those with HIV

31 HIV POCT: advantages and disadvantages Advantages: a) Rapid assessment of pregnant women considered at high-risk of HIV for initiation of prevention of mother to child transmission (PMTCT). b) Immediate linking to HIV care of transient, high-risk individuals should their screening test return reactive. c) Delivery of HIV screening in remote communities, particularly in the developing world. d) Healthcare or non-healthcare exposure to suspected HIV-positive individual.

32 HIV POCT: advantages and disadvantages Disadvantages: a) Cost of POC testing is approximately $13/test (Canadian) versus $1.78/test for standard serological screening. b) Proficiency and quality may not be possible if few tests are performed per site or multiple operators are performing POCT. c) Potential for false positives if used in general population. d) Psychosocial barriers to testing are equally present with POCT as serological screening in northern and rural communities.

33 Potential cost savings? Prevention of mother to child transmission (PMTCT): Each case prevented saves between $250,000 to $1.4 million 1,2 Earlier HIV diagnosis in adults: If caught earlier in disease process (CD4 350 cells/mm3), savings of $6000/year 2 1. Immergluck et al. Pediatrics, April (4). 2. Krentz and Gill. AIDS Research and Treatment 2012.

34 Future directions: STBBI testing Take a closer look at STBBI testing data for 2011 to 2012 Define variables for multivariate analysis: RHA Ordering medical practitioner Age of ordering practitioner When training was completed by ordering practitioner Individual sites (high risk vs. low risk patients) Use findings to help direct education and resources to optimize STBBI testing

35 Future directions: HIV POCT Pilot of POCT in Bruntwood RHA: ED and labour floor Health Sexuality and Harm Reduction (HSHR) Team and Street Connections Discussion of POCT with Klinic and Main Street Project Discussion of POCT with HSC Emergency Evaluation of data to determine additional sites based on high prevalence Further refinement of delivery of POCT on a provincial scale: To discuss with Ontario, Alberta, Saskatchewan and BC

36 Objectives 1. Briefly review the common technologies used in STBBI testing 2. Review the unique trends of STBBI testing observed in Manitoba 3. Discuss the optimal approach for HIV testing in Manitoba