April 2003
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HIV and AIDS Among Youth in Canada
Introduction
Although youth (defined here as those aged 10 to 24 years) currently constitute a small proportion of the total number of reported HIV and AIDS cases in Canada, they are a group that has been greatly affected by the HIV/AIDS epidemic at a global level. According to the most recent UNAIDS report, an estimated 11.8 million people aged 15-24 years are living with HIV/AIDS, and half of all new infections worldwide are occurring among young people.1 Youth, in general, are vulnerable to HIV infection as a result of many factors, including risky sexual behaviour, substance use (including injecting drug use), and perceptions that HIV is not a threat to them. Young Canadians require the necessary information and skills to help them to adopt and maintain behaviours that are protective against HIV. This Epi Update provides the most current information on the status of HIV and AIDS among Canadian youth. HIV-related risk behaviours in this population are also highlighted.
AIDS Data2
As of June 30, 2002, 18,332 AIDS cases with age information had been reported to the Centre for Infectious Disease Prevention and Control (CIDPC). Of these, 627 (3.4%) were among youth aged 10 to 24 years.
As seen in Table 1, of the cumulative reported AIDS cases in youth aged 10 to 19 years of age, almost two thirds of cases were attributed to recipients of blood and blood products. Among youth aged 20 to 24 years of age with AIDS, almost half were attributed to men who have sex with men (MSM), and 20% to heterosexual contact.
Table 1: Number of reported AIDS Cases with Associated Exposure Categories (%) for Individuals 10 to 24 Years of Age in Canada, Diagnosed up to June 30, 2002.
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IDU = Injecting Drug Users, MSM = Men who have sex with men
1 Percentages based on the total number of cases minus those reports for which exposure category was unknown or "not identified."
* Mode of transmission is known but cannot be classified into any of the major exposure categories.
HIV Testing Data2
Data received from provincial and territorial HIV testing programs do not allow separation of the 10 to 14 and 20 to 24 year age groups before 1998, thus restricting the analysis of HIV test reports for youth.
As of June 30, 2002, 46,801 positive HIV tests with age information have been reported to CIDPC. Of these, 684 (1.5%) were among youth aged 15 to 19 years, and 12,595 (26.9%) were among individuals aged 20 to 29 years.
The proportion of females among positive HIV test varies considerably by age and is highest among adolescents and young adults. In 2001, females accounted for 44.5% of positive HIV test reports among those aged 15 to 29 years, an increase from 41% in 2000.
For the first half of 2002, heterosexual contact, MSM and injecting drug use accounted for 40%, 40%, and 15% respectively of reported positive HIV tests with known exposure category among those aged 20 to 29 years. Heterosexual contact and injecting drug use accounted for 55% and 36% of reported HIV tests with known exposure category among those aged 15 to 19 years (n=19).
A cumulative total of 708 positive HIV test reports had been received for individuals less than 15 years of age by June 2002. Among the 354 cases in this group with known exposure category information, perinatal transmission and exposure to infected blood or blood products accounted for over 90% of cases.
HIV Incidence and Prevalence among Youth
HIV prevalence and incidence information, in conjunction with HIV/AIDS surveillance data, are more useful than surveillance data alone for depicting the current magnitude of the HIV epidemic in various population sub-groups. To date, a small number of Canadian studies have examined HIV prevalence or incidence among youth, although most research has involved higher risk populations:
In the Vancouver Injection Drug User Study (VIDUS), the prevalence of HIV among injecting drug users aged 24 years and younger during the period 1996-2001 was 17%. HIV incidence among participants in this age category was reported as 2.96 for males and 5.69 for females per 100 person years.3
In the Montreal Street Youth Cohort study (MSYC), participants between 14 and 25 years old have been observed since January 1995. HIV prevalence at study entry in the cohort was 1.4% (14 of 1013 subjects). HIV incidence up to September 2000 was 0.69 per 100 person years.4 Among male participants in the Montreal Street Youth study in 2000 who reported having sex with men, the prevalence of HIV was 4.9% and incidence was 1.2 per 100 person years.4,5
An HIV prevalence of 0.25% was observed in the mid-1990s among young offenders aged 12 to 19 years in British Columbia, many of whom reported a history of injecting drug use.6
Sentinel hospital surveillance of HIV infection in Quebec (early 1990s)7, a study of women seeking prenatal care in British Columbia (early 1990s)8, and a survey of youth from across Canada involved in an international exchange program (early to mid 1990s) 9 reported prevalence rates of 0.04% to 0.08% among young people aged 14 to 25 years. In a study in the late 1990s of women seeking abortions in Montreal, the prevalence of HIV among those aged 20 to 24 years was 0.0015%, and there were no infections detected among women under 20 years of age.10 It should be noted that these latter studies involved relatively small, non-representative samples of youth, and, thus, a zero to very low HIV prevalence rate is not necessarily reassuring.
Risk Behaviour Data Among Youth
Research shows that Canadian youth begin to have sexual intercourse at a relatively early age:
A substantial proportion of young people report having multiple sexual partners in the past year:
Among sexually experienced, single respondents (those never-married, divorced and widowed) in the 1996 NPHS, 29.4% of males aged 15 to 19 years had had more than one sex partner in the past 12 months, and 27.5% of males aged 20 to 24 years had had more than one sex partner in this same time period. In comparison, 21.8% of females aged 15 to 19 years had had more than one intercourse partner in the past 12 months, and the same percentage of females (21.9%) aged 20 to 24 years had had more than one intercourse partner in this time frame.11
In a study of young gay and bisexual men aged 15 to 30 in Vancouver, 16% of the study subjects reported selling sex for money or drugs. HIV prevalence among those subjects that had engaged in prostitution was significantly higher than those that did not (7.3% vs. 1.1%), and incidence was higher as well (4.7 per 100 person years vs. 0.9 per 100 person years).12
Research suggests that many Canadian youth are having unprotected sexual intercourse. Not using condoms appears to be more common among young women than it is among young men:
Among sexually active youth aged 15 to 19 years in the 1994 NPHS (excluding subjects who had a single sex partner and who were married, common-law, divorced, or widowed), 51% of females and 29% of males reported never or only sometimes using a condom in the past year.13 The corresponding percentages among those aged 20 to 24 years were 53% and 44%.13
In an ongoing study of
Montreal street youth, only 13.2% of participants reported always using condoms during vaginal intercourse, and only 32.4% reported always using condoms during anal intercourse.14The extent of unprotected intercourse among youth is further captured in rates of chlamydia and gonorrhea among those ages 15 to 24 years:
Research reveals that levels of injecting drug use and injecting risk behaviours among youth, particularly those who are street-involved, require ongoing assessment:
In a study of IDUs in Calgary in 1998, 46% of participants who were under age 25 years reported that they had borrowed injection equipment in the previous six months compared to 24% of participants who were aged 25 years or older.17
Recent results from the ongoing Montreal Street Youth Cohort Study showed that 47.2% of participants had a history of injecting drug use.4 Also alarming was the incidence of the initiation of injecting drug use in street youth, estimated to be 7.9 per 100 person-years.18
Comment
HIV/AIDS is affecting many subgroups of the Canadian population, including youth. Although the limited data that are available suggest that HIV prevalence is currently low among youth, sexual risk behaviour and STD data clearly indicate that the potential for HIV spread exists among young Canadians. More incidence and prevalence information as well as trend data on HIV-related risk behaviours are needed in order to guide and evaluate prevention programs for young Canadians. Epidemiologic and behavioural data for high-risk youth, such as street youth, are also needed to assess fully the risk of HIV transmission among Canada's youth population.
References
UNAIDS. Report on the global HIV/AIDS epidemic. July 2002, Geneva.
Health Canada. HIV and AIDS in Canada, surveillance report to June 30, 2002. Division of HIV/AIDS Surveillance, CIDPC, Health Canada, November 2002.
Miller CL, Tyndall M, Li K, Laliberte N, Spittal P, Schecter MT. High Rates of HIV Positivity Among Young Injection Users. Can J Infect Dis 2001; 12(Suppl B):65B {Abstract 340P}.
Roy E, Haley N, Leclerc P, Cédras L, Boivin JF. HIV incidence in the Montreal Street Youth Cohort (MSYC). Can J Infect Dis 2002; 12(Suppl A):49A {Abstract 317}.
Roy E, Hayley N, Boivin JF, Frappier JY, Claessens C, Lemire N. Étude de cohort sur l'infection as VIH chez les jeunes de la rue de Montréal. Final report to LCDC, March 1998 and Roy E (personal communication to M. Nguyen, Division of HIV Epidemiology, Bureau of HIV/AIDS, STD and TB, LDCD, HPB, Health Canada March 2000).
Rothon D, Strathdee SA, Cook D, Cornelisse PGA. Determinants of HIV-related high risk behaviours among young offenders: a window of opportunity. Can J Public Health 1997; 88(1):14-17.
Alary M, Joly JR, Parent R, Fauvel M, Dionne M. Sentinel hospital surveillance of HIV infection in Quebec. CMAJ 1994; 151(7):975-80.
Pi D, Ballem PJ, Schechter MT. The B.C. prenatal study: 1989-94. Final Report to LCDC, January 1995.
Morrisset R, Czyziw E, Lambert J. HIV infection in young Canadian adults before and after an international exchange program: 1986-96. 6th Conference of the International Society of Travel Medicine, Montreal, Canada, June 1999.
Remis RS, Leclerc P, Palmer RW, Eason EL, Lebel F, Fauvel M. HIV prevalence and incidence and reported risk factors among women undergoing abortion in Montreal. Can J Infect Dis 1997; 8(Suppl A):33A {Abstract 242} and Leclerc P (personal communication to M. Nguyen Division of HIV Epidemiology, Bureau of HIV/AIDS, STD and TB, LDCD, HPB, Health Canada).
Maticka-Tyndale E, Barrett M, McKay A. Adolescent sexual and reproductive health in Canada: a review of national data sources and their limitations. Can J Hum Sex, 2000; 9(1):41-65.
Weber AE, Craib KJP, Chan K, Martindale SL, Miller ML, Schechter MT, Hogg RS. Sex trade involvement and rates of human immunodeficiency virus positivity among young gay and bisexual men. Int J Epidemiol, 2001; 30(6):1449-54.
Galambos NL, Tilton-Weaver LC. Multiple-risk behaviour in adolescents and young adults. Health Rep 1998; 10(2):9-20.
Roy E, Haley N, Leclerc P, Lemire N, Boivin J-F, Frappier J-Y, Claessens C. Prevalence of HIV infection and risk behaviours among Montreal street youth. Int J STD AIDS 2000; 11(4):241-247.
Health Canada. STD Data Tables Appendix 1.1. Division of Sexual Health Promotion and STD Prevention and Control, CIDPC, Health Canada. http://www.phac-aspc.gc.ca/std-mts/
Health Canada. STD Data Tables Appendix 2.2. Division of Sexual Health Promotion and STD Prevention and Control, CIDPC, Health Canada. http://www.phac-aspc.gc.ca/std-mts/
Guenter CD, Fonesca K, Nielsen DM, Wheeler VJ, Pim CP. HIV Prevalence Remains Low Among Calgary's Needle Exchange Program Participants. Can J Public Health 2000; 91(2);129-132.
Roy E, Haley N, Leclerc P, Boivin JF, Cédras L. Drug use behaviours of new injectors in the Montreal street youth cohort. Can J Infect Dis 2000; 11(Suppl B):54B {Abstract 301}.
For more information please contact:
Division of HIV/AIDS
Epidemiology & Surveillance Centre for Infectious Disease Prevention & Control Public Health Agency of Canada Tunney's Pasture, Postal Locator 0900B1 Ottawa, ON K1A 0L2 Tel: (613) 954-5169 Fax: (613) 946-8695 |
Health Canada