Surveillance Report to December 31, 2001

April 2002

Division of HIV/AIDS Epidemiology and Surveillance
Centre for Infectious Disease Prevention and Control
Public Health Agency of Canada

HIV and AIDS in Canada - Surveillance Report to December 31, 2001
72 Pages - (490 KB)
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Information to the readers

The Divisions of HIV/AIDS Epidemiology and Surveillance, and Retrovirus Surveillance at the Centre for Infectious Disease Prevention and Control, Health Canada, are pleased to provide you with HIV and AIDS in Canada: Surveillance
Report to December 31, 2001.

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 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 December 31, 2001, and Reported to CIDPC up to February 11, 2002
1.	Number of positive HIV test reports by year of test
2.	Cumulative number of positive HIV test reports occurring in adults and children by gender between November 1, 1985 and December 31, 2001
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, 2001 and December 31, 2001
5A.	Number of positive HIV test reports by province/territory and gender between November 1, 1985 and December 31, 2001
5B.	Number of positive HIV test reports by province/territory and year of test
6.	Number of positive HIV test reports by exposure category and province/territory between January 1, 2001 and December 31, 2001
SECTION II Report of the Canadian Perinatal HIV Surveillance Program, 1984-2001
7.	Number of Canadian perinatally HIV-exposed infants by year of birth and maternal exposure category, 1984-2001
8.	Number of Canadian perinatally HIV-exposed infants by year of birth, current status and use of antiretroviral therapy (ART) for prophylaxis, 1984-2001
9.	Cumulative number of Canadian perinatally HIV-exposed infants by geographic region and current status, 1984-2001
SECTION III AIDS in Canada: AIDS Surveillance to December 31, 2001, and Reported to CIDPC up to February 11, 2002
10.	Number of reported AIDS cases by year of diagnosis to December 31, 2001 (all ages)
11.	Cumulative number of reported AIDS cases grouped by age at AIDS diagnosis and gender up to December 31, 2001
12.	Number of reported adult AIDS cases (>= 15 years) by year of diagnosis and gender
13A.	Number of AIDS cases by age group and year of diagnosis
13B.	Number of male AIDS cases by age group and year of diagnosis
13C.	Number of female AIDS cases by age group and year of diagnosis
14A.	Number and percentage distribution of adult AIDS cases (>= 15 years) by exposure category and year of diagnosis
14B.	Number and percentage distribution of adult male AIDS cases (>= 15 years) by exposure category and year of diagnosis
14C.	Number and percentage distribution of adult female AIDS cases (>= 15 years) by exposure category and year of diagnosis
14D.	Number and percentage distribution of AIDS cases among children (< 15 years) by exposure category and year of diagnosis
14E.	Total number of AIDS cases among adults (>= 15 years), by exposure category and age group up to December 31, 2001
14F.	Total number of AIDS cases in children (< 15 years) by exposure category and age group up to December 31, 2001
15A.	Number of AIDS cases (all ages) by province/ territory and gender up to December 31, 2001
15B.	Number of AIDS cases (all ages) by province/ territory and year of diagnosis
15C.	Number of male AIDS cases (all ages) by province/territory and year of diagnosis
15D.	Number of female AIDS cases (all ages) by province/territory and year of diagnosis
16.	Number and percentage distribution of all AIDS cases (all ages) by province/territory and exposure category to December 31, 2001
17.	Number of AIDS cases (all ages) by year of diagnosis and ethnic status
18.	Reported deaths among reported AIDS cases among adults and children by year of death
SECTION IV 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 surveillance report presents HIV and AIDS surveillance data to December 31, 2001, reported to the Centre for Infectious Disease Prevention and Control (CIDPC) from Canadian provinces and territories. This section highlights the main findings in the data through text and figures and is followed by detailed tables with the underlying data.

HIV and AIDS surveillance data, as presented in this 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 came forward for testing, were given a diagnosis of HIV infection and were reported. 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 represents those who sought medical care, were given a diagnosis of AIDS and were reported to CIDPC. The number of reported AIDS cases, therefore, does not represent true AIDS incidence.

The Division of HIV/AIDS Epidemiology and Surveillance has produced estimates of HIV prevalence to the end of 1999 and HIV incidence in 1999. These estimates were calculated using a combination of methods and 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 1999 there were approximately 49,800 people in Canada living with HIV (including those living with AIDS) and 4,190 people newly infected with HIV in 1999. Furthermore, of the 49,800, an estimated 15,000 were living with HIV but were unaware that they were infected.

HIV Surveillance Data

There have been 50,259 positive HIV tests reported to CIDPC since HIV testing began in Canada in November 1985 (Table 1). There was a 30% decrease in the number of positive HIV tests reported annually, from 2,988 in 1995 to 2,119 in 2000. In 2001, there was slight increase in this number, to 2,172 positive tests reported. Regional trends are outlined in Figure 1.

Adult females accounted for 14.4% of cumulative reported positive HIV tests with known age and gender between November 1985 and December 2001. On an annual basis, this proportion increased from 10.7% in the period between 1985 and 1995 to 21.8% in 1998 and to 24.9% in 2001 (Tables 3B and 3C). When examined by age group, the proportion of females among adult AIDS cases is highest among those aged 15-29 years. As outlined in Figure 2, this proportion has increased from 14.6% in the period between November 1985 and December 1995 to 44.5% in 2001 (Table 3B and 3C).

There was a steady increase in the proportion of positive HIV test reports in the heterosexual exposure category,¹ from 8.2% in 1985-1995 to 28.4% in 1999. There was a slight decrease, to 25.6%, in this proportion in 2000 followed by an increase to 32.8% in 2001 (Figure 3 and Table 4A).

The proportion of positive HIV test reports among adults attributed to the exposure category men who have sex with men (MSM) decreased from 72.0% in the period between 1985 and 1995 to 37.0% in 1999, then rose to 41.8% in 2000, and dropped to 36.6% in 2001 (Table 4A and Figure 3). The proportion of positive HIV test reports among adults attributed to injecting drug users (IDU) decreased from a peak of 33.7% in 1996 to 24.6% in 2001.

¹ Note: 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).

FIGURE 2
Proportion of female among adult positive HIV test reports by age group and year of test

FIGURE 3
Proportion of adult positive HIV test reports by exposure category and year of test

AIDS Surveillance Data

Since the beginning of the epidemic in the early 1980s, there have been 18,026 AIDS cases reported to CIDPC (Table 10). The annual number of AIDS diagnoses, after adjustment for reporting delay, reached a peak in the mid 1990s and has declined since this time. However, there has been a declining rate of decrease over the last few years at the national level. In addition, there is regional variability in the recent trend, with some provincial groupings showing a continuing decrease, a leveling off or, for others, a slight increase in 2001.

A major factor in the initial decline in AIDS cases (as seen in Figure 4) during the late 1990s was the delayed or prevented onset of AIDS with the use of highly effective antiretroviral therapy since 1995-1996. Reasons for the overall declining rate of decrease, as well as for the regional variation in the recent trend in delay-adjusted AIDS cases, remain unclear. Possible issues include the development of resistance to antiretrovirals and the uncertain duration of the drug effects. There is also growing concern that reporting of AIDS diagnoses is becoming increasingly delayed and underreported to both provincial and territorial ministries of health and subsequently to CIDPC.

FIGURE 4
Reported AIDS cases and AIDS cases adjusted for reporting delay by year of diagnosis

Adult females accounted for 7.8% of the total cumulative reported AIDS cases up to December 31, 2001, where age and gender were reported. This proportion increased from 4.6% in 1990 to 8.3% in 1995, followed by a sharp increase to 16.4% in 1999. The proportion decreased to 11.1% in 2000 and increased to 15.7% in 2001 (Table 12). The largest proportion of female cases is among the 15-29 year age group. The proportion of females among reported AIDS cases in this age group rose from 9.2% (146/1,581) before 1992 to 31.1% (23/74) in 1997 and to 43.8% (7/15) in 2001 (Tables 13B and 13C).

The proportion of reported adult AIDS cases attributed to the heterosexual exposure category increased to 28.8% in 1999, dropped to 23.9% in 2000 and increased to 35.6% in 2001. The proportion among MSM has steadily declined over the last decade, to 44.7% in 1999, followed by an increase in 2000 to 48.9% and a decline again to 44.6% in 2001. A steady rise in the proportion of IDU, from 2.3% in the period between 1979 and 1991 to 21.1% in 1998, was followed by a levelling off until a decline was seen in 2001 to 14.4% of all reported adult AIDS cases (Table 14A).

As outlined in Figure 6, the proportion of reported AIDS cases among the ethnic category “Whites” decreased from 87.7% before 1992 to 66.0% in 2001. The proportion of reported AIDS cases attributed to “Blacks” increased from 7.2% in 1992 to 14.8% in 1999 then dropped to 10.5% in 2000, rising again in 2001 to 13.4%. The proportion among Aboriginal groups increased from 1.7% in1992 to 10.7% in 1999 and has since decreased to close to 7.3% for the last 2 years of reporting.

Interpretation

Several findings from the most recent surveillance data are worth noting and following in the coming months. The number of positive HIV test reports among MSM have not continued to rise, as was seen in 2000, but have decreased slightly in the last year. It is also encouraging to observe the continued downward trend in the number and proportion of both positive HIV test reports and reported AIDS diagnoses attributed to IDU. However, there appears to be a shift in the epidemic toward the exposure categories associated with heterosexual transmission. Another finding of concern is the rising proportion of females in the 15-29 year age group among both positive HIV test reports and reported AIDS diagnoses. In the coming months, we will be examining these recent trends in further detail.

FIGURE 5
Proportion of reported adult AIDS cases by exposure category and year of diagnosis

FIGURE 6
Proportion of reported AIDS cases by ethnic category and year of diagnosis

 Note: There are different vertical scales for white and non-white ethnic categories