Trends in HIV incidence in Ontario based on the detuned assay: Update to December 2002 Robert S. Remis, Carol Major, Carol Swantee, Margaret Fearon, Robert W. H. Palmer, Evelyn Wallace, Elaine Whittingham Department of Public Health Sciences, University of Toronto HIV Laboratory, Laboratory Services, Ontario Ministry of Health and Long-Term Care Public Health Branch, Ontario Ministry of Health and Long-Term Care Ontario HIV Treatment Network 5th Annual Research Day Toronto, Ontario, November 3-4, 2003

MOHLTC, Laboratories Branch, IMC – 2001 Introduction Serodiagnostic data may be useful for surveillanceSerodiagnostic data may be useful for surveillance Testing of HIV-positive specimens using less sensitive (detuned” or STAHRS) assay permits the identification of persons who recently seroconverted (e.g.<4 months)Testing of HIV-positive specimens using less sensitive (detuned” or STAHRS) assay permits the identification of persons who recently seroconverted (e.g.<4 months) Allows the calculation of HIV incidence density, an important indicator usually difficult to measureAllows the calculation of HIV incidence density, an important indicator usually difficult to measure

MOHLTC, Laboratories Branch, IMC – 2001 Study objectives To estimate HIV incidence density among persons undergoing HIV testing according to exposure category and region of testTo estimate HIV incidence density among persons undergoing HIV testing according to exposure category and region of test To monitor trends in HIV incidence density among specific populations particularly affected by the HIV epidemicTo monitor trends in HIV incidence density among specific populations particularly affected by the HIV epidemic

MOHLTC, Laboratories Branch, IMC – 2001 Data collection and management Questionnaire sent with all HIV-positive resultsQuestionnaire sent with all HIV-positive results and 1 in 200 sample of HIV-negative results Data collected on risk factors for HIV infection and HIV test historyData collected on risk factors for HIV infection and HIV test history Questionnaire may be returned byQuestionnaire may be returned by mailmail faxfax telephone interviewtelephone interview Data entered in Microsoft AccessData entered in Microsoft Access

MOHLTC, Laboratories Branch, IMC – 2001 Laboratory methods Abbott 3A11 EIA kit modified as follows:Abbott 3A11 EIA kit modified as follows: serum diluted to 1:20,000serum diluted to 1:20,000 incubation period reduced to 30 minutesincubation period reduced to 30 minutes cut-off value increasedcut-off value increased For specimens tested in October 2001 or later, we used Organon-Teknika Vironostika assay allowing for different “window period” at different cut-off ( days)For specimens tested in October 2001 or later, we used Organon-Teknika Vironostika assay allowing for different “window period” at different cut-off ( days)

MOHLTC, Laboratories Branch, IMC – 2001 Study questionnaires mailed and returned, October 1999 to December %78%73%73%69%71%70% 3,1613,4196,580HIV-positiveHIV-negativeTotal 8 mon. 4 mon. ProportionReturnedMailed Kaplan - Meier returned by Questionnaires2,1872,4404,627

MOHLTC, Laboratories Branch, IMC – 2001 Exposure category classification according to HIV test requisition, returned questionnaires and modeled distribution, HIV-positives HIV test requisition Returned questionnaires among NIR Projected final distribution MSMMSM-IDUIDUEndemic HR hetero LR hetero OtherNIR ,71154%2%10%7%7%19%2% %3%7%25%5%16%4%1, %3%8%17%6%17%3% Total3,1651,049100%3,165100% %NIR54%

MOHLTC, Laboratories Branch, IMC – 2001 HIV incidence (per 100 person-years) for selected exposure categories by health region ,6031,76346,03440,674646, ,9101,31128,29922,465318, ,157823,8833,84370, MSM MSM MSM-IDU MSM-IDU IDU IDU HR hetero HR hetero LR hetero LR hetero IncidenceTestedIncidenceTestedIncidenceTestedIncidence Overall Rest of Ontario OttawaToronto Tested 22, ,85314,366257,343

MOHLTC, Laboratories Branch, IMC – 2001 MSM: HIV incidence by six-month period and region,Ontario, October1999-December 10th 2002

MOHLTC, Laboratories Branch, IMC – 2001 IDU: HIV incidence by six-month period and region,Ontario, October1999- December 10th 2002

MOHLTC, Laboratories Branch, IMC – 2001 High risk heterosexuals: HIV incidence by six-month period and region, Ontario,October1999-December 10th 2002

MOHLTC, Laboratories Branch, IMC – 2001 Low risk heterosexuals: HIV incidence by six-month period and region, Ontario, October1999-December 10th 2002

MOHLTC, Laboratories Branch, IMC – 2001 Summary of findings Exposure category distribution among thoseExposure category distribution among those with risk factor data not representative Trends in HIV incidenceTrends in HIV incidence MSM: highest in Toronto but decreasing;MSM: highest in Toronto but decreasing; intermediate and stable in Ottawa and elsewhere IDU: high in Ottawa; lower elsewhere appears to be decreasing in Ottawa and TorontoIDU: high in Ottawa; lower elsewhere appears to be decreasing in Ottawa and Toronto HR heterosexual: Incidence apparently increasing in OttawaHR heterosexual: Incidence apparently increasing in Ottawa

MOHLTC, Laboratories Branch, IMC – 2001 Interpretation Number of discordant samples and HIV tests by exposure category modeledNumber of discordant samples and HIV tests by exposure category modeled Since persons who test may not be representative and data quality is inconsistent, true HIV incidence and HIV prevalence cannot be derived directly from dataSince persons who test may not be representative and data quality is inconsistent, true HIV incidence and HIV prevalence cannot be derived directly from data Thus,interpretation of HIV incidence must incorporate knowledge of patterns in HIV test seeking behaviours; measured HIV incidence likely higher than true incidenceThus,interpretation of HIV incidence must incorporate knowledge of patterns in HIV test seeking behaviours; measured HIV incidence likely higher than true incidence

MOHLTC, Laboratories Branch, IMC – 2001 Conclusions HIV serodiagnostic program extremely useful for HIV surveillanceHIV serodiagnostic program extremely useful for HIV surveillance Due to important problems in missing and unrepresentative data on risk factors and HIV test history, available data must be enhanced through supplementary means on an ongoing basisDue to important problems in missing and unrepresentative data on risk factors and HIV test history, available data must be enhanced through supplementary means on an ongoing basis Detuned assay provides a critical indicator of trends in the epidemic at low costDetuned assay provides a critical indicator of trends in the epidemic at low cost

MOHLTC, Laboratories Branch, IMC – 2001 Acknowledgements At the HIV LaboratoryAt the HIV Laboratory Lisa Santangelo and Cindi Farina, data collectionLisa Santangelo and Cindi Farina, data collection Lynda Healey, detuned assayLynda Healey, detuned assay Elaine McFarlane, data entry screensElaine McFarlane, data entry screens Len Neglia, mail-out of questionnairesLen Neglia, mail-out of questionnaires Regional PHLs, mail-out of negative questionnairesRegional PHLs, mail-out of negative questionnaires Physicians who prescribe HIV testing and provide supplementary dataPhysicians who prescribe HIV testing and provide supplementary data Ontario HIV Treatment Network and the Centre for Infectious Disease Prevention and Control, Health Canada for fundingOntario HIV Treatment Network and the Centre for Infectious Disease Prevention and Control, Health Canada for funding