Tuberculosis Elimination in Canada Back to Basics Richard Long, MD University of Alberta The Lung Association: TB Elimination 2016 Toronto, ON, November 15-16, 2016
TB Elimination: Back To Basics Financial Interest Disclosure (over the past 24 months) Dr. Richard Long I have no conflict of interest.
Definitions: Pre-Elimination: <10 notified TB cases (all forms) per million population and year. To be achieved in Canada by 2035. Elimination: <1 notified TB case (all forms) per million population and year. To be achieved in Canada by 2050. World Health Organization
Tuberculosis in Canada, 2012 (PHAC)
Arden House Conference on Tuberculosis, Harriman, New York, 1959 Tuberculosis control has progressed to the point where virtual elimination of the disease as a public health problem appears to be within reach The remarkable progress made against tuberculosis since the advent of chemotherapy has mitigated the fear that used to be felt about the disease. Unfortunately, it has also been accompanied by some complacency and loss of interest in finishing a task that once was considered extremely urgent. Semin Resp Crit Care Med 2004; 25: 255-69.
National TB rate per 100,000 Actual incidence of tuberculosis in Canada 1989-2015, and projected rates based on pre-elimination targets set in 1997 and 2006 8 7 6 5 4 3 2 1 0 Actual incidence 1997 Target 2006 Target 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 CMAJ 2015; 187: 1191-1192
Cases per 100,000 population Crude Tuberculosis Rate in Canada by Population Group (Three Year Rolling Average) 30 25 Canadian-Born Aboriginal 20 15 Foreign-Born 10 5 Canadian-Born Non- Aboriginal 0 2000 2002 2004 2006 2008 2010 2012 2014 Year Can Respir J 2013; 20(4): 223-230
To get there we must focus on three areas: 1. TB in the Foreign Born 2. TB in Indigenous Peoples (First Nations, Métis and Inuit) 3. Federal Provincial/Territorial Collaboration
To get there we must focus on three areas: 1. TB in the Foreign Born
Proportion (%) Proportion of New Immigrants to Canada From Europe vs. Asia & Africa 80 70 Europe 60 50 Asia & Africa 40 30 20 10 0 1961-1970 1971-1980 1981-1990 1991-2000 2001-2010 2011-2014 Year Can RespirJ 2015; 22:317-321
Number of New Immigrants from High TB Incidence Countries, Per 100,000 Population 700 600 Canada USA 500 400 300 200 100 0 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Year World Health Organization; Citizenship and Immigration Canada; Statistics Canada; US Department of Homeland Security; US Census.
Proportion of New Immigrants to Canada & the USA from High Incidence Countries of Origin 80 70 60 Canada USA 50 40 30 20 10 0 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
Number of Cases 30000 25000 Number of US TB Cases Reported in US-Born and Foreign-Born Persons, 1993-2014 Unknown Origin US Born Cases Foreign Born Cases 20000 15000 10000 * 5000 0 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 Year
Crude Tuberculosis Rates in Canada and the United States, 1989-2015 12 10 Canada 8 USA National 6 Tuberculosis Rate (per 100,000) 4 2 0 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 Year
Age and sex adjusted incidence of pediatric tuberculosis by population group and time period in Alberta, 1990-2014.
Number of Cases 30 Figure 2: Number of pediatric tuberculosis cases in 5-year periods by population group in Alberta, 1990-2014 25 20 15 10 5 0 1990-1994 1995-1999 2000-2004 2005-2009 2010-2014 Year CBO-CB CBO-FB FB RFN
How effective is Canada s TB Surveillance Strategy in Identifying Immigrants at Risk of Developing and Transmitting Pulmonary TB? A Population-Based Cohort Study (L. Asadi) Permanent residents, aged 15-64 years, who arrived in Alberta between 2002-2013 223,225 IRCC Referrals Non-Referrals 5500 217,657 PTB Cases (2004-13) PTB Cases (2004-13) 50 184 C + PTB 141/10 5 15/105 CRUDE RATES 28/10 5 HRC S + PTB 31/10 5 16/10 5 HRC
% 100 Baseline characteristics of 234 foreign-born culture-positive pulmonary TB patients aged 15-64 years and diagnosed in Alberta between 2004 and 2013 90 80 70 60 50 40 30 20 10 0 0-149 150-200 >200 Incidence in Country of Birth Cavitation Smear Positive Referrals Non-referrals
Months in Canada before diagnosis of culture-positive pulmonary tuberculosis in 234 foreign-born persons by referral status Medium 11 33 Mean 19 39 0 5 10 15 20 25 30 35 40 45 Months in Canada Referrals Non-referrals
Figure 3: Transmission Events (TST Conversions and Secondary Cases) Arising from the 234 Permanent Residents who developed culture-positive PTB ---- represents transmissions to close contacts *secondary cases were not also counted as TST conversions.
Smear-negative cases are symptomatic 50% of the time and intermittently excrete small numbers of bacilli. Smear-positive cases develop within the same timeframe as smearnegative cases but are symptomatic 90% of the time and more infectious. Minimal smear-negative disease does not necessarily progress to more advanced smear-positive disease.
Referral Non-referral
Can J Public Health 2013; 104(1): e22-e27
CBO Canadian born other, FBO Foreign-born other, CBA Canadian-born Aboriginal, FBSSA Foreign-born Sub-Saharan-Africa PLoS One (2014) 9 (6): eq8993.doi: 10-1371/journal.pone.0098993
We need to be concerned about the conditions of settlement and the circumstances that promote reactivation of LTBI in migrant communities Are we providing support for migrants; are we ensuring their social participation, access to healthcare and rights to freedom from discrimination?
1. TB in the foreign-born - considerations Re-institute the long form of the census Work with Immigration, Refugees and Citizenship Canada and Public Health Agency of Canada towards revision of the surveillance referral process Support initiatives aimed at expanded surveillance and targeted treatment of LTBI Support of MDR-TB management capacity in major immigrant-receiving provinces Support migrant integration
To get there we must focus on three areas: 2.TB in Indigenous Peoples (First Nations, Métis and Inuit)
From the Arden House perspective, the equivocal historical impact of chemotherapy on TB incidence is consistent with two interpretations. One is the belief that endogenous reactivation of old TB infections contributes the majority of morbidity during the decline of an epidemic. If so, curative therapy for TB disease would lessen incident cases only decades later when the reservoir of infection would be nearing depletion without replenishment. Conversely, if recent transmission of MTB infection were contributing to TB incidence more than believed, failure to implement treatment programs for rendering incident cases non-contagious would have diluted chemotherapy s influence on near-term incidence because transmission would continue. Semin Resp Crit Care Med 2004; 25: 255-69
Tuberc Lung Dis 1993; 74: 244-53
Can Respir J 2013; 20(4): 223-230
Highly Infectious Source Case(s) Revised from Am Rev Tuberc 1957; 75: 432-41
Outbreaks disrupt routine TB control activities and could hinder elimination efforts at the local level if further generations of transmission occur, notably if the prevalence of LTBI has been increased as a result. Outbreaks also unveil pre-existing weaknesses in TB control activities such as absent or insufficient infection control, diagnostic delays or incomplete evaluation and treatment of contacts. Semin Resp Crit Care Med 2004; 25: 255-69
Each of the 222 true potential TB transmitters diagnosed in 2007 and 2008 had a 30 month transmission window 2007 2008 1 2 3 4 All DNA Fingerprinting was performed by NML using 24 loci MIRU-VNTR 222
TB Transmission, Prairie Provinces, 2007-2008 222 Canadian-born Potential TB Transmitters Indigenous 198 (89.2%) 24 Non-Indigenous (10.8%) 1025 or 94.5% of all transmission events (120 secondary cases) 60 or 5.5% of all transmission events (6 secondary cases)
Rate per 100,000 persons Rate Ratio TB Incident Rate Ratio: Indigenous vs. Non-Indigenous Canadian-Born 40 40 35 35 30 30 25 25 20 20 15 15 10 5 Indigenous Rate Non-Indigenous Rate Rate Ratio 10 5 0 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 Year 0
In their book, The White Plague, Rene and Jean Dubos warned of the dangers of treating the symptoms of pathology that is disease and ignoring the social factors that produce susceptibility. In the Many Farms community-health experiments on the Navajo Reservation in the 1950s they were disillusioned when they could not put an end to TB or other diseases that were sustained by social circumstance. Members of the Arden House conference were troubled by visions of TB evading [elimination] by aligning itself into social disparities thereby taking advantage of elusive barriers that would interfere with treatment campaigns.
NEJM 2015; 373:1748-54
2. TB in indigenous peoples - considerations Outbreak and high incidence communities Communities becoming an equal partner in TB control Implementing the TB Patients Charter of Tuberculosis Care Early diagnosis; effective case and contact management Expanded programs of prevention an elimination strategy Implementation of the Virtual clinic model to the middle and far North Engage with other Federal departments and agencies to address socioeconomic factors that contribute to TB
To get there we must focus on three areas: 3.Federal Provincial/Territorial Collaboration
Public Health 1959 Curative treatment of tuberculosis is a public health obligation. Arden House Conference on Tuberculosis 1990 Among basic strategies that are consistently effective for TB elimination: Direct government responsibility for diagnosis, treatment and prevention of tuberculosis (the government is responsible by law for assuring that tuberculosis is identified early and that cure of the patients is achieved). First IUATLD (European Region)/WHO TB Elimination Workshop at Wolfheze, Netherlands
(Re-)establishment and/or maintenance of a national tuberculosis network in terms of funding/human resources and facilities is vital Eur Respir J 2002; 19:765-75
The Canadian TB Elimination Network PHAC CTBEN FPT- TB Working Group Communicable and Infectious Disease Steering Committee Public Health Network Council Sponsor: National Collaborating Centres for Infectious disease Indigenous health Determinants of health
One of the basic elements of the World Health Organization global STOP TB initiative is to monitor and evaluate performance and impact, which is a responsibility of public health agencies working on TB control World Health Organization. Stop TB Partnership. The Stop TB Strategy. WHO 2006.
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