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HIV and AIDS in CanadaSurveillance Report to June 30, 2004November 2004 Surveillance and Risk Assessment Division PDF Version ISBN 0-662-68564-4 - (On-line) ISBN 0-662-38681-7 Acknowledgements: National level HIV and AIDS surveillance is possible as a result of all provinces and territories participating in, and setting directions for, HIV and AIDS surveillance. Accordingly, the Centre for Infectious Disease Prevention and Control acknowledges the provincial/territorial HIV/AIDS coordinators, laboratories, health care providers and reporting physicians for providing the non-nominal confidential data that enable this report to be published. Without their close collaboration and participation in HIV and AIDS surveillance, the publication of this report would not have been possible. A complete listing of these contributors is available in Appendix 5. We also thank Scientific Publication and Multimedia Services, for its contribution in editing and producing the report. N.B. This document must be cited as the source for any information extracted and used from it. Suggested citation: Public Health Agency of Canada. HIV and AIDS in Canada. Surveillance Report to June 30, 2004. Surveillance and Risk Assessment Division, Centre for Infectious Disease Prevention and Control, Public Health Agency of Canada, 2004. Surveillance and Risk Assessment Division Information to the readers of HIV and AIDS in CanadaOn behalf of the HIV/AIDS Surveillance Section, I would like to present you with the HIV and AIDS in Canada: Surveillance Report to June 30, 2004. This report is part of a semi-annual series providing a review of available HIV and AIDS surveillance data in Canada. The HIV/AIDS Surveillance section is part of the Surveillance and Risk Assessment Division, at the Centre for Infectious Disease Prevention and Control. This section is responsible for data collection and management, analysis and report production. In addition, we continue to improve data quality, define and set surveillance standards, as well as support the use of these data to influence programmatic and policy action. The main findings of the surveillance data are outlined in the section entitled At a Glance, and this is followed by a series of tables summarizing the underlying data. Technical notes in addition to references and data sources are available in the Appendices. Explanatory details specific to provincial or territorial surveillance data issues are located at the beginning of each section. A further description of HIV and AIDS surveillance data is available in the HIV/AIDS Epi Updates reports that are also available on our website listed on the front cover of this report. The publication of this report would not be possible without the submission of HIV and AIDS surveillance data from all provinces and territories. Their ongoing contribution to national HIV and AIDS surveillance is gratefully acknowledged and is further listed in Appendix 5. Yours sincerely Jennifer Geduld, MHSc Table of Contents
At a GlanceIntroductionThe following report outlines HIV and AIDS surveillance data providing a description of persons who have been diagnosed with HIV and AIDS in Canada. Surveillance data understate the magnitude of the HIV epidemic and consequently do not represent the number of people infected with HIV (prevalence) or the number infected each year (incidence). Some of the reasons for this include the fact that surveillance data are subject to delays in reporting, underreporting and changing patterns in HIV testing behaviours (who comes forward for testing). In addition, surveillance data can only tell us about persons who have been tested and given a diagnosis of HIV or AIDS and not those who remain untested and undiagnosed. Furthermore, because HIV is a chronic infection with a long latent period, many persons who are newly infected in a given year may not be diagnosed until later years. It is important to be cautious when interpreting the surveillance data for the first half of the reporting year because of small sample sizes and delayed and underreporting. A full description of the limitations of these data is outlined in Appendix 2. The Centre for Infectious Disease Prevention and Control (CIDPC) will continue to monitor the surveillance data and will clarify whether these findings are sustained when the full year is reported. HIV Surveillance DataA total of 56,523 positive HIV tests have been reported to CIDPC from November 1985 (when reporting began) up to June 30, 2004. The rising trend in positive test reports outlined in previous reports appears to be continuing. The annual number of reports has increased from 2,112 in 2000 to 2,499 in 2003 (Table 1). In addition, in the first six months of 2004, there were 155 more positive HIV tests reported compared with the first six months of 2003. Females represent a growing proportion of positive HIV test reports, reaching 26.6% in the first half of 2004. This increasing trend is being observed particularly among younger women who represented 42.6% of the 15-29-year age group and 23.9% of the 30-39-year age group in the first six months of 2004 (Figure 1). FIGURE 1 Men who have sex with men continue to represent the largest number and proportion of positive HIV tests reports. Injecting drug use was the second exposure category up until 1998, showing a peak over 33% in 1996 and 1997 and decreasing to 18% in 2003 and the first six months of 2004. Starting in 1999, the heterosexual category became the second largest exposure category, increasing from 7.5% prior to 1995 and reaching over 30% by 2001 (Figure 2). Within the heterosexual category, positive test reports attributed to persons from HIV-endemic countries have increased from 2.9% in 1998 to 8.6% in the first six months of 2004. The sub-category for those with no further risk information than heterosexual sex has also increased over time, from 2.4% before 1995 to 10.9% in the first six months of 2004. FIGURE 2 AIDS SurveillanceIt is important to note the limitations associated with AIDS diagnoses reported in the first half of 2004. As outlined in Section III, no data were available from Quebec and could therefore not be included in the national summary. For this reason, annual trends as well as figures for reported AIDS diagnoses are limited to data to the end of 2003. A total of 19,468 AIDS diagnoses have been reported to CIDPC up to June 30, 2004 (Table 13). The proportion of females among reported AIDS diagnoses has increased from 6.1% during the period between 1979 and 1994 to 25.2% in 2003 (Table 15). This increasing trend is being seen particularly in the 15-29- year age group, in which female youth represented 9.8% of all AIDS diagnoses in this group prior to 1994 and 41.0% in 2003 (Tables 16B and 16C). Men who have sex with men represent the largest exposure category among cumulative AIDS diagnoses, but annual trends demonstrate a decreasing proportion, from 78.0% prior to 1994 to 34.6% in 2003 (Table 17A, Figure 3). The combined heterosexual exposure category, however, has increased from 10.6% to 44.7% during the same period with the largest increases in the sub- categories origin from an HIV-endemic country and heterosexual sex as the only known risk (NIR HET). As outlined in Figure 4, White Canadians represent a decreasing proportion of AIDS diagnoses, from 86.4% prior to 1994 to 53.8% in 2003. This decline has been coupled with increases among both Black and Aboriginal Canadians. Black Canadians represented 8.3% of diagnoses before 1994 and 20.7% among Aboriginal Canadians in 2003; during the same period the proportion among Aboriginal Canadians increased from 1.3% to 14.4% (Table 20, Figure 4). FIGURE 3 FIGURE 4 InterpretationSome of the reasons for the increase in positive HIV test reports may be changes in HIV testing patterns, reporting delays, and/or underlying infection rates. However, this increase is at least in part due to changes in immigration policies at Citizenship and Immigration Canada1 that were implemented in 2002. These changes include the addition of HIV testing to the routine immigration medical assessment and reduced restrictions on certain groups of immigrants (such as family class and refugees) who would have previously been considered medically inadmissible because of excessive demands on the Canadian health care system. From January 2002 to June 30, 2004, 772 individuals tested positive for HIV infection during their routine immigration medical assessment in Canada2 , accounting for 12% of the positive HIV test reports during this period (note that this excludes HIV-positive applicants who apply from outside Canada). Those applicants who test positive in Canada are included in the national surveillance numbers, since they are handled in the same manner as all other positive HIV tests and included in provincial/territorial HIV reporting to CIDPC. These new policies may also be contributing to some of the changes observed in the distribution of positive test reports in exposure category and ethnic category in both HIV and AIDS surveillance. Another important finding that will have implications for guiding prevention and treatment programs is the continuing rising trend in the proportion of positive HIV test reports among females in each age group. This is especially true among those in the younger age groups, who are soon going to represent half of the positive test reports among all young Canadians. 1 Citizenship and Immigration Canada. Immigrant and Refugee Protection Act. Statutes of Canada 2001. Chapter 27. Also available at URL: http://www.cic.gc.ca/. 2 Dr. S. Martin, Acting Director, Immigration Health Program Elaboration, Medical Services Branch, Citizenship and Immigration Canada: personal communication. PDF Version
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Last Updated: 2004-12-01 |