TUBERCULOSIS CONTROL 2005 2006 2007 2008 ANNUAL REPORT
Table of Contents
4 Foreword 5–6 Executive Summary 7 Tuberculosis Active Cases 8–9 TB Active Cases 10 Incidence Rates 11 Incidence Rates, Sub-Vancouver Areas 12 General Description of Active Cases 13 Demographics 14 HIV Status 15 Mortality 16–17 Types of Tuberculosis 18 Resistance & Location of Treatment 19 Latent Tuberculosis Infection 20 Latent Tuberculosis Infection Rates 21 Demographic Characteristics
23 TB Services For Aboriginal Communities (TBSAC) 24 Introduction 25–27 Statistics 28 Other Activities 29 Discussion 30–31 Update & Future Plans 32 Acknowledgements
33 Research 2005—2008 34–35 Publications
Foreword This report presents selected statistical and epidemiological information referring to tuberculosis (TB) in the province of British Columbia derived from the activities of the Division of Tuberculosis Control, BC Centre for Disease Control for the calendar years 2005–2008.
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On October 21st 2003 a new clinical TB module was introduced allowing the division to go largely paperless. The module is contained within the integrated Public Health Information System (iPHIS). In April 2003 the module was introduced in the Yukon and is available for read only access for most health units throughout the province. The information contained in this report is wholly derived from statistics contained in iPHIS maintained in the Division of Tuberculosis Control. Although tuberculosis is a notifiable disease, the Division of Tuberculosis Control is informed of cases from several sources including directly from the Provincial Laboratory Services of the BC Centre for Disease Control and through Pharmacy Services of BC Centre for Disease Control which is responsible for dispensing all anti-tuberculosis medication throughout the province. These additional reporting mechanisms help to ensure the Division of Tuberculosis Control is advised of all active and suspect tuberculosis treated in the province of British Columbia. The 2005–08 Annual Report is offered with high degree of confidence in its accuracy. The care of Aboriginal peoples on reserve is administered by the Federal Government through First Nations and Inuit Health (FNIH) who contract with the Division of Tuberculosis Control for this service. All Aboriginal peoples living off reserve are the responsibility of the provincial Ministry of Health Services. For this report the term ‘Aboriginal peoples’ is a collective name used to describe Status and nonStatus North American Indians (commonly known
as First Nations), Métis (mixed First Nations and European ancestry), and Inuit (of Arctic Canada) peoples. Although the term First Nations is widely used in Canada, Status and non-Status Indians are the legally defined terms recognized by the Department of Indian and Northern Affairs. A reserve has been defined as a tract of land set apart for use and benefit by and Indian Band. The 2005–08 Annual Report includes details of in-patient treatment of tuberculosis patients which is not directly administered by the Division of Tuberculosis Control. The care of these patients is carried out in a TB unit specifically dedicated to the care of patients with TB, located in the Vancouver General Hospital and Health Sciences Centre and run by the Division of Respiratory Medicine. TB cases diagnosed between January 1st, 2005 and December 31, 2008 for whom data were entered into the database up to April 2009 were included in the analysis. Incidence rates (IR) of TB in British Columbia as a whole and in each health region were calculated, as were age specific rates. Population figures were based on the information provided by Statistics Canada (Statistics Canada, Population section, BC Stats, Ministry of Finance and Corporate Relations). I am grateful for the assistance of Dr. Eduardo Hernandez, Claus Sorensen, Maria MacDougall, Ritinder Harry, Ms. Valerie Lee, Sunny Mak and Ms. Fay Hutton in the preparation of this report.
Dr. R.K. Elwood, MB, MRCP(UK), FRCPC Provincial Director Division of Tuberculosis Control
Executive Summary In 2005–08 there were 277,336,290 and 305 reported cases of tuberculosis in British Columbia (BC) providing a rate varying from 6.5–7.9 per 100,000 for an average rate of 7.1/100,000. over the 4 years of the report. The national rate for Canada for 2008 is 4.5/100,000 with an average rate of 4.85/100,000 over the last 4 years. BC remains above the national rate and in 2008 there were 1,490 cases reported in Canada. Active cases: Rates for various health regions vary across the province. High rates compared to the provincial figures persist for Vancouver Coastal (11.9), Richmond (11.6) and Fraser (7.6) health service delivery areas, rates that exceed the provincial rate (7.1/100,000 population). All figures refer to the 4 year average. The Downtown East Side rates remain consistently high although not at the rates seen in 2001 and 2002 when the rates were 85.5 and 64.2/100,000 respectively. The rates varied from a low of 29.4 in 2008 to a high of 46.3/100,000 in 2006. 2008 saw 25% reduction in rates. A substantial outbreak occurred in the Central Vancouver Island HSDA, primarily centred around the city of Port Alberni, over the span of this report. Rates went from 3.2/100,000 in 2005 to 41.8 in 2006 and ‘07 with a fall to 35.5/100,000 in 2008. This represented 38 cases of active disease diagnosed over 4 years. A similar outbreak has recently occurred in the Okanagan. The median age of cases was 48 years. The rate was higher in men than women (7.7 vs 6.4) overall, but higher in women compared to men in individuals aged 15–34 years old. In individuals ≥ 60 years the rate of tuberculosis was considerably higher in men than in women. Rates of tuberculosis among Aboriginal peoples living on and off reserve rose from 23.3/100,000 in 2005 to 34.2 in 2008. Aboriginal peoples living
off reserve continue to have the highest incidence rate of tuberculosis among any group including the foreign born. With rates varying from 29.4 in 2005–48.0/100,000 in 2007. The rate in 2008 was 43.9/100,000. Of note, 2 Métis and 2 Inuit cases were included in the figures over the 4 year period. The rate among the foreign born averaged 18.9/100,000 while the rate among the Canadian born non-Aboriginal people was 1.3/100,000 averaged over the 4 years. The top 6 countries of origin of the foreign born cases were in descending order India, China, Philippines, Vietnam, Hong Kong and South Korea. The rate of HIV positivity among active cases has remained fairly steady over the 4 years of this report at 6% average, although not all cases were tested. Of the HIV positive cases, 28.8% were foreign-born, 32.9% were Canadian-born non-Aboriginal people and 34.2% were Aboriginal peoples. Of the 305 cases in 2008, 182 were tested for HIV (62%). Drug resistance rates remain low with 10.4 % being resistant to at least 1 drug. 75 (7.77%) were mono-resistant, 9 (0.9%) cases were multiple drug resistant and 17 (1.7%) cases poly-resistant treated over the 4 years. The great majority of drug resistant TB was found in the foreign born, and Aboriginal peoples were the least likely to harbour resistant organisms. The commonest single drug resistance was to isoniazid (36.6%, n = 37).
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Executive Summary Seventy-six percent of patients were treated with self administered treatment and 17% received directly observed therapy. On average over the 4 years 76.9% of cases completed treatment satisfactorily. Reasons not to complete treatment include death, moved out of province or were lost to follow-up. Relatively few were due to noncompliance (1.2%). 8.7 percent (n = 24) of cases had a reactivation of TB in 2005 with 9.5, 9.7 and 11.8% in subsequent years. Relapsed pulmonary cases were drug resistant, on average, 18.3% on sensitivity testing.
Preventive Therapy:
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In 2005–08, 5,654 patients were placed on preventive therapy for latent tuberculosis infection for an average of 1,413 cases a year with the commonest reason being contact with an active case or a positive skin test not further defined. The completion rate for preventive therapy was 60% (range 55–65%). The majority were foreign born (70%). The commonest causes of non-completion were drug reactions followed by poor compliance.
Skin Test and BCG: Over the 4 years covered by this report 92,704 TB skin tests were performed in the province. Of these 16,983 (18%) tests were positive. The commonest reason for skin testing was for employment and student screening followed by contact tracing and screening of Aborginal communities. BCG is no longer administered in the province of BC.
Contacts: Contact tracing is an important component of TB Control activities and the number of cases diagnosed as a result of contact tracing has risen steadily over the last 4 years from 2.5% in 2005 to 6.9 % in 2008. On average 3,164 annual contacts were screened for active or latent disease over the 4 years. The rates of active TB in all contacts exceeds 700/100,000.
Admission: A designated ward is located in the Vancouver General Hospital which contains 12 beds. Over the 4 years admissions to the ward varied from 86 cases in 2005 to 113 cases in 2008. A number of cases were readmitted in different years. Fifty-five percent of cases admitted to the ward were foreign born while Canadian born and Aboriginal peoples were equally represented.
Health regions: Rates for various health regions vary across the province. Over the four years, the Vancouver, Richmond, Fraser North and Fraser South health service delivery areas have consistently had rates exceeding the provincial rate (7.1/100,000 population average over 4 years). The highest incidence rate was observed in Richmond-Vancouver HSDA which varied from 13.2 to 16.6/100,000 over the 4 years, while the lowest incidence rates were typically observed in North Vancouver Island and the East/West Kootenay. Reference should be made to GIS maps for further details. Due to a significant outbreak in Central Vancouver Island over the last 3 years the rates increased from 2.0/100,000 in 2005 to over 6.3/100,000 in 2007 in that region. Forty two percent ( n = 512) of all TB cases lived in Vancouver and 37% (n = 458) in Fraser North or Fraser South.
Tuberculosis Active Cases TB Active Cases 8–9 Incidence Rates 10
Incidence Rates, 11 Sub-Vancouver Areas General Description of Active Cases 12 Demographics 13 HIV Status 14 Mortality 15 Type of Tuberculosis 16–17 Resistance & Location 18 of Treatment
TB ACTIVE CASES 2005
2.6
4.6
5.6
2.6 3.3 0.0 2.6 15.8
7.5
0.0
6.1
2.0
7.3
0.0
1.3
2.7
Rates per 100,000 population by HSDA
2.0
0.0
SW BC Inset
3.7
8
2.6
4.6
15.8
1.3
7.5
Cases
Rate
HSDA
Health Service Delivery Area
11
East Kootenay
2
2.7
12
Kootenay Boundary
1
1.3
13
Okanagan
0
0.0
14
Thompson Cariboo Shuswap
7
3.3
21
Fraser East
16
6.1
22
Fraser North
42
7.5
23
Fraser South
47
7.3
31/32
Richmond-Vancouver
124
15.8
33
North Shore/Coast Garibaldi
7
2.6
41
South Vancouver Island
13
3.7
42
Central Vancouver Island
5
2.0
43
North Vancouver Island
0
0.0
51
Northwest
2
2.6
52
Northern Interior
8
5.6
53
Northeast
3
4.6
Notes: Map classification by natural breaks method. Data are aggregated for Richmond-Vancouver HSDAs.
2006
10.6
0.0
5.7
4.5 1.4 0.9 4.5 16.6
10.1
4.5 3.8
6.0
10.5
1.8
2.6
1.3
Rates per 100,000 population by HSDA
6.0 3.4
0.9
SW BC Inset
0.0
4.5 1.8
16.6 6.0
HSDA
Health Service Delivery Area
11
East Kootenay
1
1.3
12
Kootenay Boundary
2
2.6
13
Okanagan
6
1.8
14
Thompson Cariboo Shuswap
3
1.4
21
Fraser East
10
3.8
22
Fraser North
57
10.1
23
Fraser South
69
10.5
31/32
Richmond-Vancouver
132
16.6
33
North Shore/Coast Garibaldi
12
4.5
41
South Vancouver Island
12
3.4
42
Central Vancouver Island
15
6.0
43
North Vancouver Island
1
0.9
51
Northwest
8
10.6
52
Northern Interior
8
5.7
53
Northeast
0
0.0
Cases
Notes: Map classification by natural breaks method. Data are aggregated for Richmond-Vancouver HSDAs.
Rate
TB ACTIVE CASES 2007
9.4
6.1
7.1
2.9 1.4 0.9 2.9 13.2
8.5
0.9
2.9 3.3
6.3
8.4
0.6
1.3
0.0
Rates per 100,000 population by HSDA
6.3
0.0
SW BC Inset
4.7
4.7
13.2
1.4
9.4
HSDA
Health Service Delivery Area
11 12
Cases
Rate
East Kootenay
0
0.0
Kootenay Boundary
1
1.3
13
Okanagan
2
0.6
14
Thompson Cariboo Shuswap
3
1.4
21
Fraser East
9
3.3
22
Fraser North
49
8.5
23
Fraser South
56
8.4
31/32
Richmond-Vancouver
107
13.2
33
North Shore/Coast Garibaldi
8
2.9
41
South Vancouver Island
17
4.7
42
Central Vancouver Island
16
6.3
43
North Vancouver Island
1
0.9
51
Northwest
7
9.4
52
Northern Interior
10
7.1
53
Northeast
4
6.1
Notes: Map classification by natural breaks method. Data are aggregated for Richmond-Vancouver HSDAs.
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2008
10.7
10.5
3.5
2.9 3.6 1.7 2.9 13.7
7.9
2.9 4.0 3.2
3.5
8.1
1.3
6.3
Rates per 100,000 population by HSDA
3.5 4.7
1.7
SW BC Inset
1.3 1.7
4.7
13.7 8.1
HSDA
Health Service Delivery Area
11 12
Cases
Rate
East Kootenay
5
6.3
Kootenay Boundary
1
1.3
13
Okanagan
11
3.2
14
Thompson Cariboo Shuswap
8
3.6
21
Fraser East
11
4.0
22
Fraser North
46
7.9
23
Fraser South
55
8.1
31/32
Richmond-Vancouver
112
13.7
33
North Shore/Coast Garibaldi
8
2.9
41
South Vancouver Island
17
4.7
42
Central Vancouver Island
9
3.5
43
North Vancouver Island
2
1.7
51
Northwest
8
10.7
52
Northern Interior
5
3.5
53
Northeast
7
10.5
Notes: Map classification by natural breaks method. Data are aggregated for Richmond-Vancouver HSDAs.
Incidence Rates Rates for various health regions vary across the province. High rates compared to the provincial figures persist for Vancouver Coastal (11.9), Richmond (11.6) and Fraser (7.6) health service delivery areas, rates that exceed the provincial rate (7.1/100,000 population). The majority of cases numerically are reported from Vancouver, Fraser South and Fraser North Heath Regions (221 cases, 71%). Over the last few years, there has been an increase in the number of cases in the Northwest and Northeast Health Regions. All figures refer to the 4 year average.
Figure 1: Tuberculosis incidence rates by Health Authority in BC at the time of diagnosis, 2005-2008
14 12
Rate per 100,000
10
10 8 6 4 2 0
2005 2006 2007 2008 All Four Years
Fraser Valley
Interior
Northern
Vancouver Coastal
Vancouver Island
7.2 9.0 7.2 7.1 7.6
1.3 1.6 1.3 3.7 2.0
5.6 5.7 7.5 7.0 6.5
12.4 13.7 10.9 10.8 11.9
2.4 4.0 4.5 3.9 3.7
Incidence Rates
Sub-Vancouver Areas Sub-Vancouver areas: The incidence rate of TB varied from 29.4 /100,000 in 2008 to 46.3/100,000 in 2006 in Downtown Eastside. Compared to 2007 there was a 25% reduction in the number of cases. The rates in Richmond remain above the provincial rate averaging 11.6/100,000 over 4 years. The Westside of Vancouver has the lowest rates averaging 5.2 /100,000. There have been no major fluctuations in rates in these areas over the 4 years.
Figure 2: Tuberculosis incidence rates in sub-Vancouver areas, 2005–2008
11
Downtown Eastside City Centre
50 Westside
Rate per 100,000
40
Midtown
North East
South Vancouver
30
NB: Map colours do not correspond with graph below
fmm
20
10
0 City Centre
2005 2006 2007 2008 All Four Years
15.8 9.0 3.5 8.6 9.1
Downtown Eastside
30.9 46.3 39.5 29.4 36.4
North East
25.2 27.9 13.7 25.1 23.0
Westside
3.9 7.0 7.7 2.3 5.2
Midtown
19.2 21.4 15.3 15.3 17.8
South
16.0 14.4 19.6 10.5 15.1
General Description of Active Cases The average age of cases was approximately 50 years (median = 48). Overall, more men than woman were diagnosed with active disease over the 4 years although in 2006 the ratio was equal. The mean was 54.3 % male and 45.7% female. Rates in men exceeded those in women (7.7 vs. 6.4/100,000). The majority of cases (75%) were diagnosed due to symptoms compatible with the site of disease while the next commonest method of diagnosis was contact tracing (5%). Occupational screening diagnosed TB in 0.6% of the cases screened for a total of 7 cases over the 4 years whereas post-landing immigrant surveillance diagnosed 45 cases representing 3.7% of cases. Thirty two cases were diagnosed at post-mortem (2.6%).
Figure 3: Average TB incident rates in BC by age and gender, 2005–2008
25
20 Rate per 100,000
12
15
10
5
0 Age ◊
