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Background: Multidrug-resistant (MDR) tuberculosis has increased among migrants in Canada. The cause(s) of this increase is unknown.Methods: We performed a retrospective cohort study in a Canadian province with substantially increased immigration between 1982-2001 and 2002-2019. The proportion of MDR tuberculosis among migrants arriving from high MDR (HMDR) tuberculosis burden countries during these 2 periods was used to estimate the proportion of cases due to immigration versus change in proportion in the country of birth. Epidemiologic, spatiotemporal, and drug resistance pattern data were used to confirm local transmission.Results: Fifty-two of 3514 (1.48%) foreign-born culture-positive tuberculosis patients had MDR tuberculosis: 8 (0.6%) in 1982-2001 and 44 (2.0%) in 2002-2019. Between time periods, the proportion of MDR tuberculosis among migrants with tuberculosis from HMDR tuberculosis countries increased from 1.11% to 3.62%, P = .003; 31.6% attributable to recent immigration and 68.4% to a higher proportion of MDR tuberculosis in cases arrived from HMDR tuberculosis countries. No cases of MDR tuberculosis were attributable to local transmission.Conclusions: In stark contrast to HMDR tuberculosis countries, local transmission plays no important role in the occurrence of MDR tuberculosis in Canada. Improved tuberculosis programming in HMDR tuberculosis countries is urgently needed. [ABSTRACT FROM AUTHOR]

Treatment of rifampin-monoresistant/multidrug-resistant Tuberculosis (RR/MDR-TB) requires long treatment courses, complicated by frequent adverse events and low success rates. Incidence of RR/MDR-TB in Canada is low and treatment practices are variable due to the infrequent experience and challenges with drug access. We undertook a retrospective cohort study of all RR/MDR-TB cases in Alberta, Canada from 2007–2017 to explore the epidemiology and outcomes in our low incidence setting. We performed a descriptive analysis of the epidemiology, treatment regimens and associated outcomes, calculating differences in continuous and discrete variables using Student's t and Chi-squared tests, respectively. We identified 24 patients with RR/MDR-TB. All patients were foreign-born with the median time to presentation after immigration being 3 years. Prior treatment was reported in 46%. Treatment was individualized. All patients achieved sputum culture conversion within two months of treatment initiation. The median treatment duration after culture conversion was 18 months (IQR: 15–19). The mean number of drugs utilized during the intensive phase was 4.3 (SD: 0.8) and during the continuation phase was 3.3 (SD: 0.9) and the mean adherence to medications was 95%. Six patients completed national guideline-concordant therapy, with many patients developing adverse events (79%). Treatment success (defined as completion of prescribed therapy or cure) was achieved in 23/24 patients and no acquired drug resistance or relapse was detected over 1.8 years of median follow-up. Many cases were captured upon immigration assessment, representing important prevention of community spread. Despite high rates of adverse events and short treatment compared to international guidelines, success in our cohort was very high at 96%. This is likely due to individualization of therapy, frequent use of medications with high effectiveness, intensive treatment support, and early sputum conversion seen in our cohort. There should be ongoing exploration of treatment shortening with well-tolerated, efficacious oral agents to help patients achieve treatment completion. [ABSTRACT FROM AUTHOR]

This study evaluated the status of native and stocked fish species in 13 prairie lakes in central Canada over eight years (2007–14) using three metrics: resource‐use (benthic versus pelagic carbon via stable isotopes); body condition (relative weight index Wr); and parasite load (cestode gut enumerations). Analyses included game and non‐game fishes, like naturally occurring northern pike, Esox lucius L., and yellow perch, Perca flavescens Mitchill, but focused on stocked walleye, Sander vitreus (Mitchill) because it supports a robust recreational fishery. Walleye and northern pike were significantly more reliant on benthic carbon than yellow perch or forage fishes (p < 0.05), but this reliance was not associated with any measured environmental variables for any species. In lakes with game fishes, forage fishes exhibited higher reliance on benthic energy, possibly due to predator avoidance strategy, particularly yellow perch. Walleye body condition index was consistently lower (<95–105) than values exhibited by the other two game fishes (81–139), and parasites were only common in walleye and associated with lake‐water salinity (r2 = 0.93, p < 0.05) and sex (p < 0.05). Based on the results, the most desirable game fish, walleye, appears less resilient to environmental variability than northern pike and yellow perch, making this species more susceptible to impacts of future climate change. [ABSTRACT FROM AUTHOR]

Rifampin is the cornerstone of care for active TB disease, forming part of all first-line treatment regimens,[3] as well as a valuable treatment for latent TB infection. Canada has already recognized the vital importance of sustainable access to crucial TB drugs in lower-income countries, becoming the largest single-country donor for first-line drugs like rifampin to the Global Drug Facility, a global bulk procurer of TB medicines.[8] Given the looming threat to both public health and patient care, we call on the Canadian government to devote similar effort and resources to ensuring continuous access at home, both through stronger regulatory measures to prevent domestic drug shortages and the authorization of alternative sources for TB drugs such as the Global Drug Facility. 8 Project profile - global drug facility: provision of anti-tuberculosis drugs.. Ottawa: Government of Canada. [Extracted from the article]

Objectives: Although a "multisite" definition of disseminated tuberculosis (DTB) exists, there is limited evidence to support its use. Herein, we sought to generate that evidence., Methods: We evaluated treatment outcomes and reporting requirements against two distinct definitions of DTB in a 15-year population-based cohort of consecutively diagnosed patients with tuberculosis (TB) in Canada. Definitions were combined in a multi-variable logistic regression to determine the risk factors for TB-related death in DTB., Results: We applied two mutually exclusive definitions of DTB to our data set: 1. "strict" - TB disease associated with a positive TB culture in blood/bone marrow or TB disease associated with a miliary pattern on chest imaging and a positive TB culture or, 2. multisite - TB disease in two or more non-contiguous sites. Among 2877 notified patients with TB, 110 (3.8%) met the strict definition, whereas 168 (5.8%) met the multisite definition. Of all 278 patients with DTB, only 135 (48.6%) were notified as DTB using International Classification of Disease codes and only 66 (23.7%) were classified as DTB by Canada's Public Health Agency. Patients with DTB by either definition were less likely to achieve cure/treatment completion and more likely to die. The risk factors for a fatal outcome included extremes of age, Canadian birth, central nervous system involvement, and HIV co-infection., Conclusion: Our findings support the combination of a strict and multisite definition of DTB for purposes of reporting consistency and investigational comparability., Competing Interests: Declarations of competing interest The authors have no competing interests to declare., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Epidemiologic research on zoonotic tuberculosis historically used Mycobacterium bovis as a surrogate measure; however, increased reports of human tuberculosis caused by other animal-associated Mycobacterium tuberculosis complex members like Mycobacterium orygis necessitates their inclusion. We performed a retrospective cohort study including persons infected with any animal-lineage M tuberculosis complex species in Alberta, Canada, from January 1995 to July 2021, identifying 42 patients (20 M bovis, 21 M orygis, 1 M caprae). Demographic, epidemiologic, and clinical characteristics were compared against persons with culture-confirmed M tuberculosis infection. The proportion of culture-positive infections caused by M orygis increased continuously from 2016 to 2020. Significantly more females at a higher median age were impacted by M orygis, with all patients originating from South Asia. Mycobacterium bovis caused significantly more extrapulmonary disease and disproportionately impacted young females, particularly those pregnant or postpartum. All infections were acquired abroad. These findings can aid in developing targeted public health interventions., Competing Interests: Potential conflicts of interest. All authors: No reported conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed. Funding to pay the Open Access publication charges for this article was provided by the Canadian Research Knowledge Network (CRKN)., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Objectives: Canada has accepted more than 25,000 Syrian refugees fearing persecution in their homeland. Canadian guidelines recommend screening recent refugees from high incidence countries for tuberculosis (TB) and latent TB infection (LTBI). The prevalence of TB in this population is unknown. A refugee clinic in Edmonton presented a unique opportunity to estimate prevalence of TB and LTBI in Syrian refugees arriving in Canada., Methods: In January 2016, 100 consecutive Syrian refugees were screened for TB with clinical assessment and LTBI using QuantiFERON Gold In-Tube assay (QFT-GIT). Patients with positive QFT-GIT were referred to Edmonton Tuberculosis Clinic (ETBC) for evaluation and, if appropriate, offered prophylaxis., Results: No cases of active TB were found. Valid QFT-GIT were measured in 99 of 100 individuals and of these, nine (9%) were positive using a threshold concentration of blood interferon-γ greater than 0.35 IU/L. Eight of the nine patients attended follow-up appointments; of these, seven began LTBI prophylaxis and all seven (78%) completed same., Conclusion: The 9% (95% confidence interval 3-15%) prevalence of LTBI was higher than expected in this population.