Epidemiology of Hepatitis B and Hepatitis C in Canada, 1999-2001

Mr. Gregory ZaniewskiEpidemiologist, Blood Borne Pathogens Section

Health Care Acquired Infections DivisionCentre for Infectious Disease Prevention and ControlPopulation and Public Health Branch, Health Canada

January 28th, 2003

Blood-borne Pathogens Section

Mandate: To provide surveillance, risk assessment, recommendations on prevention and control of viral hepatitis and emerging blood-borne pathogens

Activities:▫ Surveillance

▫ Targeted research

▫ Knowledge synthesis, analysis and policy development

▫ Recommendations on prevention and control

▫ Establishing networks

HB and HC Surveillance in CanadaHepatitis B and hepatitis C are reportable in Canada through the National Notifiable Disease Reporting System.

The usefulness of the data is affected by the nature of the infections, the inconsistency in reporting practices across jurisdictions, and the lack of information on the risk factors associated with transmission.

The enhanced surveillance of acute hepatitis B and hepatitis C was established in 1998 to address the limitations of routine surveillance.

As of April, 2002 the enhanced surveillance has been fully integrated with the strain surveillance of the National Microbiology Laboratory.

Developed and are currently using an upgraded surveillance tool that is site based

Enhanced Hepatitis Strain Surveillance System

ObjectivesEstimate the incidence rate for acute hepatitis B and C

Investigate the risk factors associated with transmission

Monitor incidence rates over time and across population groups

Monitor the genotypic distribution of infection over time by mode of transmission, population group and geography

Support the development of evidence-based prevention and control programs for hepatitis B and C

Evaluate the effectiveness of preventive strategies and public health responses

Identify at-risk populations for targeted research and intervention

ChronicAcute ChronicAcuteYear

ΒTwo Health Regions* Four Health Regions† Six Health Regions‡ Seven Health Regions∑ Eight Health Regions

Provisional data for 2002

73014471192002∑3218862009672001‡

31531211691852000†

2744114846641999*

49618138101998β

Hepatitis C CasesHepatitis B Cases

Summary of Identified Acute and Chronic Hepatitis B and C by Year: Enhanced Hepatitis Strain

Surveillance System

Incidence rates of acute hepatitis B (per 100,000 person-year) by age, 1999-2001

0

1

2

3

4

5

6

< 5 5 - 9 10-19 20-29 30-39 40-59 60 +Age Group

Rat

e

Rate-1999Rate-2000Rate-2001

Source: Enhanced Hepatitis Strain Surveillance system, HCAID

Identification rates of chronic or like-chronic hepatitis B (per 100,000 person-year) by age, 1999-2001

0

10

20

30

40

50

60

70

80

90

< 5 5 - 9 10-19 20-29 30-39 40-59 60 +

Age Group

Rat

eRate-1999Rate-2000Rate-2001

Source: Enhanced Hepatitis Strain Surveillance system, HCAID

Incidence rate of acute hepatitis C (per 100,000 person-year) by age 1999-2001

0

1

2

3

4

5

6

7

8

< 5 5 - 9 10-19 20-29 30-39 40-59 60 +Age Group

Rat

eRate-1999Rate-2000Rate-2001

Source: Enhanced Hepatitis Strain Surveillance system, HCAID

Identification rate of chronic or like-chronic hepatitis C (per 100,000 person-year) by age, 1999-2001

0

20

40

60

80

100

120

140

160

180

200

< 5 5 - 9 10-19 20-29 30-39 40-59 60 +

Age Group

Rat

eRate-1999Rate-2000Rate-2001

Source: Enhanced Hepatitis Strain Surveillance system, HCAID

Risk factor groups for Acute and Chronic Hepatitis B and C in four health regions, 1999-2001

0 10 20 30 40 50 60 70 80 90 100

Acute HBV (N=154)

Acute HCV (N=218)

Chronic HBV (N=468)

Chronic HCV (N=4,164)

Proportion of all Cases

Injection Drug Use Sexual Health Care Acquired Other Subcutaneous Others Unknown

Source: Enhanced Hepatitis Strain Surveillance system, HCAID

Risk factor groups for Acute and Chronic Hepatitis B and C in four health regions by sex, 1999-2001

0 10 20 30 40 50 60 70 80 90 100

Acute HBV - Male

Acute HBV - Female

Acute HCV - Male

Acute HCV - Female

Chronic HBV - Male

Chronic HBV - Female

Chronic HCV - Male

Chronic HCV - Female

Proportion of Cases

Injection Drug Use Sexual Health Care Acquired Other Subcutaneous Others Unknown

Source: Enhanced Hepatitis Strain Surveillance system, HCAID

Aboriginal People in Canada

Approximately 1 million Aboriginal People in Canada representing ~ 4% of population

Aboriginal defined as First Nations, Métis and Inuit

About half of Aboriginal population is urban, half in Northern/remote/rural communities

Lower level of health status amongst Aboriginal people in Canada

Population and Area

The Assembly of First Nations represents approximately 633 bands across Canada.The population represented by these bands is approximately 642, 414 Aboriginals. Of this total, approximately 58.4% live on Reserve or Crown Land.There are approximately 2370 reserves across Canada, covering 2.8 million hectares (approx. 6.9 million acres).

Source: Natural Resources Canada, 2002-05-18

1/3 fewer70% 44% Own home

1/3 higher16% 26% Lone parent Unemployed rate

Almost twice as many16% 30% Children under 15 living in lone

parent families

Twice as many16% 35% Incidence of low income families

1/3 as many28% 9% 65yrs+ with investment income

1/2 as many19% 8% 65yrs+ with private pensions

1/4 less$21,028 $15,866 Average income for those 65+

1/3 less$25,435 $17,823 Average Income for those 15+

Twice as high10% 20% Unemployed Rate

4 times fewer12% 3% % over 65 yrs

Much younger20% 34% % under 15yrs

227,285 on Res.79% % Off-Reserve

4% of Canada28,528,125 1,101,960 Total population

Aboriginal Condition

General Population

Aboriginal Ancestry

Comparison of Selected Characteristics of Aboriginal Ancestry Population With the General Population of Canada

Compiled and Analyzed by Prof. V.F. Valentine, CAP, Socio-Demographic Statistical Analysis and Research Project, January 21, 1999. - Source: Statistics Canada, 1996 Census

Selected Health Indicators AmongCanada’s Aboriginal Population

62% among First Nations, 72% among Inuit, 2 times higher among Aboriginal youth

2000Tobacco Use

0-15 times higher than in the general population

3-5 times higher in Inuit population

1994Suicide

8 out of 10 Aboriginal women in Ontario experienced family violence

75% to 90% of women battered, 40% of children experience physical abuse

1989Family Violence

3-5 times higher, increase in type II diabetes

2000Diabetes

16% of new HIV infections reported among Aboriginals and especially women

1999-2000

HIV/AIDS

OutcomeYearHealth Indicator

Incidence rates of hepatitis B and C among Aboriginal and Non-Aboriginal Canadian-Born

8.4

2.25

18.8

1999

3.41

1.13

3.84

2001

Hepatitis CHepatitis B

10.56.82.45.6Rate Ratio

1.372.571.630.88

Non-Aboriginal Canadian-Born

14.417.53.894.96Aboriginal

2001200020001999

Distribition of mutually exclusive risk factor groups for acute and chronic hepatitis B cases among Aboriginals and Non-

Aboriginals, 1999-2001 combined

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Aboriginal Non-Aboriginal Aboriginal Non-Aboriginal

Prop

ortio

n of

cas

es

IDU Sexual Health Care AcquiredOther subcutaneous Other Unknown

Acute Chronic

Distribution of mutually exclusive risk factor groups for acute and chronic hepatitis C cases among Aboriginals and Non-

Aboriginals, 1999-2001 combined

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Aboriginal Non-Aboriginal Aboriginal Non-Aboriginal

Prop

ortio

n of

cas

es

IDU Sexual Health Care AcquiredOther subcutaneous Other Unknown

Acute Chronic

(1) IDU(2) Unknown(3) Drug snorting

(1) IDU(2) Unknown(3) Drug Snorting(3) Sex with Hep C

Top 3 Acute Risk Factors – Hepatitis C

(1) IDU(2) Heterosexual(3) Drug Snorting(3) MSM

(1) Unknown(2) IDU(3) Drug Snorting(3) MSM

Top 3 Acute Risk Factors – Hepatitis B

higher53.768.4% Male – Hepatitis C

½ as many73.038.5% Male – Hepatitis B

Similar 33.030.9Mean Age Acute Hepatitis C

Similar 34.436.8Mean Age Acute Hepatitis B

8 times higher2.0616.9Rate of Acute Hepatitis C (not

standardized)

4 times as high 1.21 4.23 Rate of Acute Hepatitis B (not standardized)

Aboriginal Condition

General Population

Aboriginal Ancestry

Summary of Data from the Enhanced Hepatitis Strain Surveillance System, 1999-2001 Comparing Aboriginal Health Factors to those of the General Population

Burden of Hepatitis C

1,000 per year8,000-10,000 per year

--5,000 per yearDeaths from chronic disease due to Hepatitis C

240,000

(0.8%)

3.9 Million (1.8%)

186,000-204,000

250,000

(0.5%)

Prevalence

3,000-7,000 per year

40,000 (1998)10,000-12,000--New Infections

CanadaUnited StatesAustralia

(1997)

United Kingdom

HCV in Aboriginal Population

Few epidemiological studies on HCV in Aboriginal population▫ First Nations 0.4% - 29.3% prevalence▫ Canadian Street Youth – 6% of Aboriginals▫ Health Can Surveillance – 17.5% prevalence

• Also >1500 Aboriginal co-infected HIV

▫ MB Cadham Provincial Lab – 8-9% prevalence

The observed inequality between aboriginals and non-Aboriginals reinforces the need for targeted research, outreach, prevention and control interventions

Acknowledgements

Leslie Forrester, David Boulos, Neil J Goedhuis, Yuanli Shi from the BBP Section

All Site Investigators