HIV and aids in Canada

Surveillance Report to June 30, 2003

Information to the readers of HIV and AIDS in Canada

The Divisions of HIV/AIDS Epidemiology and Surveillance, and Retrovirus Surveillance at the Centre for Infectious Disease Prevention and Control (CIDPC), Health Canada, are pleased to provide you with the HIV and AIDS in Canada: Surveillance Report to June 30, 2003.

The Division of HIV/AIDS Epidemiology and Surveillance is responsible for all data analyses, writing and coordination of the publication of this report. This Division works in close collaboration with the Division of Retrovirus Surveillance, which manages the collection of HIV and AIDS surveillance data.

Please note details about specific provincial surveillance data issues at the beginning of each section. Please note that the number of positive HIV test reports for the province of Quebec is based on the minimum number of HIV positive individuals. Please refer to the Limitations outlined in our Technical Notes section for further explanation.

We are continuing to make improvements to this report and always welcome and appreciate your comments and suggestions.

Yours sincerely,

Table of Contents

At a Glance
TABLES
SECTION I HIV in Canada: Positive HIV Test Reports to June 30, 2003
1.	Number of positive HIV test reports by year of test (all ages)
2.	Cumulative number of positive HIV test reports occurring in adults and children by gender between November 1, 1985, and June 30, 2003
3A.	Number of positive HIV test reports by age group and year of test
3B.	Number of positive HIV test reports among males by age group and year of test
3C.	Number of positive HIV test reports among females by age group and year of test
4A.	Number of positive HIV test reports among adults (>= 15 years) by exposure category and year of test
4B.	Number of positive HIV test reports among adult males (>= 15 years) by exposure category and year of test
4C.	Number of positive HIV test reports among adult females (>= 15 years) by exposure category and year of test
4D.	Number of positive HIV test reports among children (< 15 years) by exposure category and year of test
4E.	Number of positive HIV test reports by exposure category and age group between January 1, 2003, and June 30, 2003
5A.	Number of positive HIV test reports by province/territory and gender between November 1, 1985, and June 30, 2003 (all ages)
5B.	Number of positive HIV test reports by province/territory and year of test (all ages)
6.	Number of positive HIV test reports by exposure category and province/territory between January 1, 2003, and June 30, 2003 (all ages)
SECTION II Report of the Canadian Perinatal HIV Surveillance Program
SECTION III AIDS in Canada: AIDS Surveillance to June 30, 2003
11.	Number of reported AIDS cases by year of diagnosis (all ages)
12.	Cumulative number of reported AIDS cases  grouped by age at AIDS diagnosis and gender up to June 30, 2003
13.	Number of reported adult AIDS cases (>= 15 years) by year of diagnosis and gender
14A.	Number of AIDS cases by age group and year of diagnosis
14B.	Number of male AIDS cases by age group and year of diagnosis
14C.	Number of female AIDS cases by age group and year of diagnosis
15A.	Number and percentage distribution of adult AIDS cases (>= 15 years) by exposure category and year of diagnosis
15B.	Number and percentage distribution of adult male AIDS cases (>= 15 years) by exposure category and year of diagnosis
15C.	Number and percentage distribution of adult female AIDS cases (>= 15 years) by exposure category and year of diagnosis
15D.	Number and percentage distribution of AIDS cases among children (< 15 years) by exposure category and year of diagnosis
15E.	Total number of AIDS cases among adults (>= 15 years), by exposure category and age group up to June 30, 2003
15F.	Total number of AIDS cases in children (< 15 years) by exposure category and age group up to June 30, 2003
16A.	Number of AIDS cases (all ages) by province/territory and gender up to June 30, 2003
16B.	Number of AIDS cases (all ages) by province/territory and year of diagnosis
16C.	Number of male AIDS cases (all ages) by province/territory and year of diagnosis
16D.	Number of female AIDS cases (all ages) by province/territory and year of diagnosis
17.	Number and percentage distribution of AIDS cases (all ages) by province/territory and exposure category to June 30, 2003
18.	Number of AIDS cases (all ages) by year of diagnosis and ethnic status
SECTION IV Mortality Due to HIV/AIDS in Canada: Surveillance to June 30, 2003
19.	Reported deaths among reported AIDS cases by year of death (all ages)
20.	Cumulative number of reported deaths among reported AIDS cases occurring in adults and children by age of death and gender up to June 30, 2003
21.	Reported deaths among reported AIDS cases among adults (>= 15 years) and children by year of death
22.	Reported deaths among reported AIDS cases among adults (>= 15 years) by year of death and gender
SECTION V International Statistics on AIDS
APPENDICES Appendix 1. Technical Notes Appendix 2. Data Limitations Appendix 3. Terminology Appendix 4. References Appendix 5. Data Sources

At a Glance

Introduction

This section highlights the main findings observed in the HIV and AIDS surveillance data reported by Canadian provinces and territories to the Centre for Infectious Disease Prevention and Control (CIDPC) up to June 30, 2003. Detailed tables follow this section presenting the underlying data.

It is important to note that reported positive HIV tests and AIDS cases as presented in this surveillance report represent only those individuals who seek testing and/or medical care. The number of positive HIV test reports provides a description of those who were tested, given a diagnosis of HIV infection and reported to CIDPC. It does not, however, represent the total number of individuals living with HIV (prevalence) or newly infected each year (incidence). Similarly, the number of reported AIDS cases does not represent true AIDS incidence but, rather, is a description of those who sought medical care, were given a diagnosis of AIDS and were reported to CIDPC.

CIDPC has produced estimates of HIV prevalence to the end of 2002 and HIV incidence in 2002. These estimates were calculated using a combination of methods, incorporating data from a wide variety of sources, including HIV test reports, AIDS case reports, population-based surveys, targeted epidemiologic studies and census data. It was estimated that at the end of 2002 there were approximately 56,000 people, range 46,000 to 66,000, in Canada living with HIV (includes those living with AIDS) and 2,800 to 5,200 newly infected with HIV in 2002. Furthermore, of the 56,000, an estimated 17,000 Canadians, or 30%, were unaware that they were infected and are consequently not represented in the HIV surveillance data. More information on the methodology and results of these estimates is available in the Canada Communicable Disease Report¹ and on our Website.

HIV Surveillance Data

There have been 53,887 positive HIV tests reported to CIDPC from November 1985 (when reporting to Health Canada began) up to June 30, 2003. The annual number of positive HIV tests (new diagnoses) reported declined from 2,990 in 1995 to 2,124 in 2000 and increased to 2,499 in 2002. There have been 1,207 positive HIV tests reported to CIDPC in the first six months of 2003 (Table 1).

Since 1985, adult females have represented 15.0% of positive HIV test reports among adults for whom age and gender were reported. Although more positive HIV tests continue to be reported among males, the proportion of females each year has risen, from 12.0% in the years between 1985 and 1997 to approximately 25% of adult positive HIV test reports from 2001 to the first half of 2003 (Figure 1) (Tables 3A and 3B).

The proportion of positive HIV test reports attributed to men who have sex with men (MSM) decreased from 67.6% in the period between 1985 and 1997 to 36.1% in 2001 but has risen to 43.5% in the first six months of 2003 (Table 4A, Appendix 1). A gradual decrease continues in the proportion of adult positive HIV test reports attributed to injecting drug use. This proportion decreased from 28.7% in 1998 to 17.5% in the first half of 2003. The diverse heterosexual exposure category includes three subcategories: sexual contact with a person at risk, origin from a pattern II country and sex with the opposite gender as the only identified risk (NIR-HET). There has been an increase in the proportion of this exposure category among positive HIV test reports, from 9.9% in the period between 1985 and 1997 to over 30% after 2001. Figure 2 outlines the distribution of exposure categories among positive HIV test reports in the previous 18 months.

FIGURE 1
Proportion of females among reported adult* positive HIV tests and AIDS cases

* >= 15 years
** For HIV, this includes 1985-1997, for AIDS this includes 1979-1997

FIGURE 2
Positive HIV test reports by exposure category, January 2002-June 2003 (all ages)

Percentages are based on total number minus reports for which exposure category was not reported or for which there was no identified risk (NIR)

AIDS Surveillance Data

It is important to note the limitations associated with AIDS cases reported in the first half of 2003 from both British Columbia and Quebec, as outlined at the beginning of Section III. For this reason, trends as well as figures for reported AIDS cases are limited to data to the end of 2002.

There have been 18,934 AIDS cases reported to CIDPC since the early 1980s (Table 11). Among reported adult AIDS cases, the proportion of females increased from 6.1% during the period 1979-1994 to 15.8% in 1999. In 2000, this proportion dropped to12.1% and has since risen to 16.5% in 2002 (Table 13, Figure 1).

Table 15A presents exposure categories of reported AIDS cases by year of diagnosis. The largest proportion of reported AIDS cases is attributed to MSM. This proportion was over 75% before 1993 and has decreased each year, to 44.7% in 2002, with the exception of an increase to 50.6% in the year 2000 (Table 15A). There was a rise in the proportion of IDU among reported adult AIDS cases from 3.3% between 1979 and 1993 to a peak of 21.5% in 1998. The proportion decreased to 14.8% in 2001 but has increased since then to 19.1% in 2002. The proportion of reported adult AIDS cases attributed to the heterosexual category has increased from 11% before 1994 to 32% in 2002.

The proportion of AIDS cases among Aboriginal people increased from 1.5% before 1994 to 9.7% in 1999, followed by a drop to 5.5% in 2001 and a subsequent rise to 12.9% in 2002. The proportion attributed to white Canadians has dropped from 87.1% in the period between 1979 and 1993 to 58.9% in 2002 (Table 18, Figure 3).

FIGURE 3
Ethnic category as a percentage of all reported AIDS cases, by year of diagnosis (all ages)

Percentages are based on total number minus AIDS cases for which ethnic category was not reported

Interpretation

It is important to be cautious when interpreting the surveillance data for the first half of the reporting year because of the small sample sizes and delayed and underreporting (Appendix 2). CIDPC will continue to monitor the surveillance data and will clarify whether these findings are sustained when reports for the full year are available.