BACKGROUND: A context-specific, spatial-temporal understanding of a chain of tuberculosis (TB) transmission can inform TB elimination strategy. METHODS: Clinical, public health and molecular epidemiologic data were used to: 1) identify and describe a complex cluster of TB cases in Alberta, 2) elucidate transmission sequences, and 3) assess case-patient mobility. Socio-economic indicators in loci of transmission and the province at large were described. Factors seen to be fostering or hampering TB elimination were identified. RESULTS: Over a 15-year period, 18 TB cases in Alberta and multiple cases in the Northwest Territories were determined to be due to the same strain. One patient was diagnosed at death; all others completed directly-observed therapy (DOT). Case-level analysis revealed that patients were highly mobile with transmission of the strain over 26,569 km2, an average of 2.8 different places of residence per patient during treatment, and contacts of sputum smear-positive cases spanning 9 of 17 regional health authorities. The majority of the contacts (57%) were attached to a single infectious case living in a homeless shelter. The three loci of transmission in Alberta were separated geographically but similar in terms of median incomes, rates of unemployment, levels of post-secondary education, and rates of population mobility (p < 0.0001). CONCLUSION: Upon review of the experience, central oversight, intra- and inter-jurisdictional coordination and DOT were seen as fostering, and the absence of 'real-time' DNA fingerprinting, social network analysis, engineering controls in shelters and better determinants of health in loci of transmission were seen as hampering TB elimination.
BACKGROUND: A context-specific, spatial-temporal understanding of a chain of tuberculosis (TB) transmission can inform TB elimination strategy. METHODS: Clinical, public health and molecular epidemiologic data were used to: 1) identify and describe a complex cluster of TB cases in Alberta, 2) elucidate transmission sequences, and 3) assess case-patient mobility. Socio-economic indicators in loci of transmission and the province at large were described. Factors seen to be fostering or hampering TB elimination were identified. RESULTS: Over a 15-year period, 18 TB cases in Alberta and multiple cases in the Northwest Territories were determined to be due to the same strain. One patient was diagnosed at death; all others completed directly-observed therapy (DOT). Case-level analysis revealed that patients were highly mobile with transmission of the strain over 26,569 km2, an average of 2.8 different places of residence per patient during treatment, and contacts of sputum smear-positive cases spanning 9 of 17 regional health authorities. The majority of the contacts (57%) were attached to a single infectious case living in a homeless shelter. The three loci of transmission in Alberta were separated geographically but similar in terms of median incomes, rates of unemployment, levels of post-secondary education, and rates of population mobility (p < 0.0001). CONCLUSION: Upon review of the experience, central oversight, intra- and inter-jurisdictional coordination and DOT were seen as fostering, and the absence of 'real-time' DNA fingerprinting, social network analysis, engineering controls in shelters and better determinants of health in loci of transmission were seen as hampering TB elimination.
Authors: T R Sterling; D Thompson; R L Stanley; P D McElroy; A Madison; K Moore; R Ridzon; S Harrington; W R Bishai; R E Chaisson; S Bur Journal: Int J Tuberc Lung Dis Date: 2000-11 Impact factor: 2.373
Authors: S M Marks; Z Taylor; N L Qualls; R J Shrestha-Kuwahara; M A Wilce; C H Nguyen Journal: Am J Respir Crit Care Med Date: 2000-12 Impact factor: 21.405
Authors: Richard Long; Denise Whittaker; Krista Russell; Dennis Kunimoto; Robert Reid; Anne Fanning; Ewa Nobert; Lyle Melenka; Wadieh Yacoub; Ravi Bhargava Journal: Can J Public Health Date: 2004 Jul-Aug
Authors: Richard Long; Vernon Hoeppner; Pamela Orr; Martha Ainslie; Malcolm King; Sylvia Abonyi; Maria Mayan; Dennis Kunimoto; Deanne Langlois-Klassen; Courtney Heffernan; Angela Lau; Dick Menzies Journal: Can Respir J Date: 2013-05-28 Impact factor: 2.409
Authors: Smit Patel; Catherine Paulsen; Courtney Heffernan; Duncan Saunders; Meenu Sharma; Malcolm King; Vernon Hoeppner; Pamela Orr; Dennis Kunimoto; Dick Menzies; Sara Christianson; Joyce Wolfe; Jody Boffa; Kathleen McMullin; Carmen Lopez-Hille; Ambikaipakan Senthilselvan; Richard Long Journal: PLoS One Date: 2017-11-14 Impact factor: 3.240