Laboratories Branch, MOHLTC, IMC – 2001 The epidemiology of HIV infection among persons from HIV-endemic countries in Ontario: Update to 2002 Robert S. Remis MD Department of Public Health Sciences University of Toronto Stigma and Discrimination on HIV/AIDS People-to-People Organization November 30, 2003, Toronto, Ontario

Laboratories Branch, MOHLTC, IMC – 2001 Acknowledgments Maraki Fikre Merid, Elaine Whittingham, Department of Public Health Sciences, University of Toronto Frank McGee, AIDS Bureau, Ontario Ministry of Health and Long-Term Care (OMHLTC) Carol Swantee, HIV Laboratory, OMHLTC Lorraine Schiedel, Public Health Branch, OMHLTC Roger Bourque, Vital Statistics Division, Registrar- General of Ontario Chee Wong, Health Planning System (HELPS) Dr. Susan King, Hospital for Sick Children HIV Endemic Task Force

Laboratories Branch, MOHLTC, IMC – 2001 Background Anecdotal case reports, especially from the Hospital for Sick Children, Toronto Growing community concern Limited research and few specific data available Formation of HIV Endemic Task Force in 1998 Mandated an epidemiologic assessment in November 1998 and initial estimates published in November 1999

Laboratories Branch, MOHLTC, IMC – 2001 Definition: HIV-endemic 1.High prevalence of HIV infection in the general population (generally greater than 1% but may be 20% or higher) and 1.Heterosexual contact the most important mode of transmission.

Laboratories Branch, MOHLTC, IMC – 2001 Study mandate Determine population born in HIV-endemic countries stratified by region of residence and country of origin Characterize incidence and prevalence of HIV infection among persons from HIV-endemic countries

Laboratories Branch, MOHLTC, IMC – 2001 Methods: Model structure Stage 1: Demographic model Estimate population by gender and country of birth (and region of residence) from 1981 to 2002; Inputs: Immigrants, births and deaths and estimated inter-provincial migrants Outputs: Population (census data for validation), AIDS-related deaths

Laboratories Branch, MOHLTC, IMC – 2001 Methods: Model structure Stage 2: HIV infection model Estimate prevalence of HIV infection by gender and country of birth from 1981 to 2002 Inputs: Number of immigrants, HIV prevalence in country of origin, AIDS progression, mother-infant HIV transmission rates, secondary sexual transmission Outputs: HIV prevalence, AIDS incidence, HIV-related mortality, number of HIV-infected mothers, HIV- infected infants and “endogenous” HIV transmissions

Laboratories Branch, MOHLTC, IMC – 2001 Methods: Model structure Goodness of fit (GOF) Model outputs were compared to observed data using the GOF statistic including: AIDS incidence, AIDS-related deaths, HIV prevalence and HIV-infected mothers and infants GOF was calculated separatelyfor males and females HIV prevalence immigration factor was adjusted to minimize the GOF statistic

Laboratories Branch, MOHLTC, IMC – 2001 Methods: Selection of countries Category 1: Countries with large population in Ontario or a large number number of HIV-infected persons were modeled individually Category 2: Countries with smaller immigrant population in Ontario were modeled regionally Category 3: Not modeled

Laboratories Branch, MOHLTC, IMC – 2001 Methods: Selection of countries CaribbeanCategory 1 6 Category 2 8 (as one group) Category 315 AfricaCategory 1 7 Category 2 17 (as four groups) Category 3 20

Laboratories Branch, MOHLTC, IMC – 2001 Methods: Data sources Population ( )Vital Statistics, Registrar General Birth data ( ) Health Planning system Death data ( )Health Planning System HIV diagnostic data ( )HIV Laboratory AIDS cases ( )AIDS Surveillance Program, Public Health Branch HIV mortality ( )Vital Statistics, Registrar General Mother-infant HIV ( ) Canadian Pediatric AIDS Research Group Ontario region

Laboratories Branch, MOHLTC, IMC – 2001 Methods: Missing data Data not available for most recent few years (births, deaths) was determined based on data for previous years Data not available by gender (deaths, births) was entered in the both sexes model and interpolated to the genders based on proportion of cases from previous years

Laboratories Branch, MOHLTC, IMC – 2001 Methods: Data adjustment Where appropriate, data was adjusted for unknown country of birth and unknown gender based on the proportions in the known AIDS cases: Under-reporting and delayed reporting HIV-infected mothers: Proportion undiagnosed HIV-infected infants: Delayed diagnosis

Laboratories Branch, MOHLTC, IMC – 2001 Results: Population “Census” populationCaribbean 264,300 African 99,600 Total363,900 However, modeled population was Caribbean 406,900 and African 156,500 for a total of 563,400 (includes second generation)

Laboratories Branch, MOHLTC, IMC – 2001 Results: Data sources HIVAdjusted HIV diagnoses: 2,071 (8.8%) among 21,453 HIV diagnoses in Ontario but 22% in 2001 and 2002 compared to 6.7% in AIDS376 cases (5.1%) among 6,952 AIDS cases reported in Ontario but 20% in 2001 and 2002 compared to 4.6% in

Laboratories Branch, MOHLTC, IMC – 2001 Results: HIV model Model fit well for most countries HIV-infected persons, 2002 Caribbean 1,366 African 1,261 Total 2,627 HIV prevalence Caribbean 0.5% (0.3% - 2.9%) Africa 1.1% (0.5% %)

Laboratories Branch, MOHLTC, IMC – 2001 Results: HIV model (cont’d) Caribbean: Four countries account for 86% of infections Jamaica494 (36%) Trinidad277 (20%) Guyana261 (19%) Haiti147 (11%) Africa: Five countries account for 66% of infections Ethiopia366 (29%) Uganda131 (10%) Somalia127 (10%) South Africa114 ( 9%) Kenya 88 ( 7%)

Laboratories Branch, MOHLTC, IMC – 2001 Results: HIV model (cont’d) Substantial HIV transmission in Canada, representing 22-59% of HIV infections Male: female ratios indicate importance of MSM- endemic, especially from Caribbean Marked increase in recent years, mostly since 1990 Annual increase of about 270 HIV infections, or about 12%, in latest year

Laboratories Branch, MOHLTC, IMC – 2001 Modeled HIV prevalence among persons born in sub-Saharan Africa or Caribbean, Ontario

Laboratories Branch, MOHLTC, IMC – 2001 Interpretation Estimates are based on modeling Thus, estimates not precise but represent rather “plausible range” Also, some parameters had to be adjusted, adding additional uncertainty Level of uncertainty not known exactly, but probably about 30%

Laboratories Branch, MOHLTC, IMC – 2001 Interpretation: Comparison with other groups Low compared to primarily affected groups Compared to other heterosexual persons in Ontario, 15-fold higher for persons from Caribbean 30-fold higher for persons from sub-Saharan Africa HIV prevalenceHIV number Proportion infections Endemic MSM IDU Other hetero ~0.7% 10-15% 5-10% ~0.03% 2,600 13,600 1,900 3,100 12% 64% 9% 15%

Laboratories Branch, MOHLTC, IMC – 2001 Interpretation: Comparison with other groups Comparison of HIV infection rates MSM 1:8 IDU 1:15 Endemic 1:140 Other heterosexual 1:3,000

Laboratories Branch, MOHLTC, IMC – 2001 Summary of findings Modeling exercise produced plausible estimates of 2,630 HIV-infected persons Caribbean 1,260; sub-Saharan Africa 1,370 Current estimate is 12% higher than the 2,350 estimated for 1998: However, 60% higher in persons from Africa and 15% lower in persons from Caribbean Reasons for change require further examination Number of HIV infections increasing substantially year over year Estimates must be considered an hypothesis Actual studies required to confirm findings