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Rapid detection and reporting of novel influenza A virus (IAV) strains are critical to prompt evaluation of a pandemic threat (1). For example, in 2009, health officials in Mexico reported [...]

Background: Studies show that more than 5.1 million deaths annually are attributed to nonoptimal temperatures, including extreme cold and extreme heat. However, those studies mostly report average estimates across large geographical areas. The health risks attributed to nonoptimal temperatures in British Columbia (BC) are reported incompletely or limit the study area to urban centers. In this study, we aim to estimate the attributable deaths linked to nonoptimal temperatures in all five regional health authorities (RHAs) of BC from 2001 to 2021., Methods: We applied the widely used distributed lag nonlinear modeling approach to estimate temperature-mortality association in the RHAs of BC, using daily all-cause deaths and 1 × 1 km gridded daily mean temperature. We evaluated the model by comparing the model-estimated attributable number of deaths during the 2021 heat dome to the number of heat-related deaths confirmed by the British Columbia Coroners Service., Results: Overall, between 2001 and 2021, we estimate that 7.17% (95% empirical confidence interval = 3.15, 10.32) of deaths in BC were attributed to nonoptimal temperatures, the majority of which are attributed to cold. On average, the mortality rates attributable to moderate cold, moderate heat, extreme cold, and extreme heat were 47.04 (95% confidence interval [CI] = 45.83, 48.26), 0.94 (95% CI = 0.81, 1.08), 2.88 (95% CI = 2.05, 3.71), and 3.10 (95% CI = 1.79, 4.4) per 100,000 population per year, respectively., Conclusions: Our results show significant spatial variability in deaths attributable to nonoptimal temperatures across BC. We find that the effect of extreme temperatures is significantly less compared to milder nonoptimal temperatures between 2001 and 2021. However, the increased contribution of extreme heat cannot be ruled out in the near future., Competing Interests: The authors declare that they have no conflicts of interest with regard to the content of this report., (Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The Environmental Epidemiology. All rights reserved.)

Background: During the first year of the COVID-19 pandemic, the proportion of reported cases of COVID-19 among Canadians was under 6%. Although high vaccine coverage was achieved in Canada by fall 2021, the Omicron variant caused unprecedented numbers of infections, overwhelming testing capacity and making it difficult to quantify the trajectory of population immunity., Methods: Using a time-series approach and data from more than 900 000 samples collected by 7 research studies collaborating with the COVID-19 Immunity Task Force (CITF), we estimated trends in SARS-CoV-2 seroprevalence owing to infection and vaccination for the Canadian population over 3 intervals: prevaccination (March to November 2020), vaccine roll-out (December 2020 to November 2021), and the arrival of the Omicron variant (December 2021 to March 2023). We also estimated seroprevalence by geographical region and age., Results: By November 2021, 9.0% (95% credible interval [CrI] 7.3%-11%) of people in Canada had humoral immunity to SARS-CoV-2 from an infection. Seroprevalence increased rapidly after the arrival of the Omicron variant - by Mar. 15, 2023, 76% (95% CrI 74%-79%) of the population had detectable antibodies from infections. The rapid rise in infection-induced antibodies occurred across Canada and was most pronounced in younger age groups and in the Western provinces: Manitoba, Saskatchewan, Alberta and British Columbia., Interpretation: Data up to March 2023 indicate that most people in Canada had acquired antibodies against SARS-CoV-2 through natural infection and vaccination. However, given variations in population seropositivity by age and geography, the potential for waning antibody levels, and new variants that may escape immunity, public health policy and clinical decisions should be tailored to local patterns of population immunity., Competing Interests: Competing interests: Maureen Anderson reports receiving a Saskatchewan Health Research Foundation Establishment Grant, in support of the present manuscript. Lesley Behl reports receving funding from the CITF via a research grant paid to the University of Saskatchewan, in support of the present manuscript. Patrick Brown reports receiving grant support from the CITF. Carmen Charlton reports receiving grant funding from Merck and support for attending meetings or travel from AMMI Canada. Karen Colwill reports receiving an honorarium for a presentation to the Ontario Society of Clinical Chemists. Dr. Colwill is also the vice president of communications for the Canadian National Proteomics Network. Tim Evans reports receiving support for the present manuscript from the CITF, and holds the role of its executive director. Anne-Claude Gingras reports receiving support for automated equipment for ELISA, housed at the Lunenfeld-Tanenbaum Research Institute (a facility supported by Canada Foundation for Innovation funding, the Ontario Government, Genome Canada and Ontario Genomics); support from the Canadian Institutes of Health Research (CIHR) for general lab operations; salary support as a Canada Research Chair (Tier 1) in functional proteomics; and from CITF and the Public Health Agency of Canada (PHAC) for assay calibration at Mount Sinai, all in support of the present manuscript. Dr. Gingras has had a contract with Providence Therapeutics (no consultation fees received), and has received grant funding from CIHR for several SARS-CoV-2 studies and from the Ontario Research Fund, outside of the present work. Dr. Gingras has served as the chair of the Institute Advisory Board of the CIHR Institute of Genetics and is a member and chair of the Human Health Therapeutics Division advisory board, National Research Council of Canada. Dr. Gingras is a member of the CITF working parties on testing and immunology, and is pillar lead of the Functional Genomics and Structure Function of CoVaRR-Net (all roles unpaid). Steven Drews reports receiving grants or contracts from CIHR and Alberta Innovates, consulting fees from Roche, support for attending meetings or travel from the Canadian Immunization Research Network and other support from Abbott. Jaspreet Jain reports receiving support from the CITF for the present manuscript. Prabhat Jha reports receiving grant support from the CITF for the Action to Beat Coronavirus study. Amanda Lang reports receiving funding from the CITF, in support of the present manuscript, for assay reagents and technologist salary. Dr. Lang has also received support from the CITF to attend a CITF meeting. Stephen Lee reports receiving funding from the CITF, in support of the present manuscript. Sheila O’Brien reports receiving payment (paid to Canadian Blood Services [CBS]) from the Government of Canada, and laboratory infrastructure from CBS, in support of the present manuscript. Chantale Pambrun reports receiving salary support from CBS, and study funding from PHAC. Olivia Oxlade is an employee of the CITF Secretariat. David Stephens reports receiving funds for a graduate student from the National Science and Engineering Research Council Emerging Infectious Disease Modelling, in support of the present manuscript. Hanna Swail reports receiving support from the CITF for the present manuscript. David Buckeridge reports receiving funding from PHAC, in support of the present manuscript. No other competing interests were declared., (© 2023 CMA Impact Inc. or its licensors.)

Background: The first case of coronavirus disease 2019 (COVID-19) in Alberta, Canada, was confirmed on March 5, 2020. Because the virus testing criteria had changed significantly over this time period, we wanted to ascertain whether previous cases of COVID-19 had been missed in the province., Methods: Our aim was to retrospectively evaluate specimens submitted for respiratory virus testing from December 1, 2019, through March 7, 2020, for undetected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections before the first confirmed case., Results: Testing of 23,517 samples (representing 23,394 patients) identified 1 patient positive for SARS-CoV-2. This specimen was collected on February 24, 2020, from a patient with symptoms consistent with COVID-19 who had recently returned from the western United States. Phylogenetic analysis confirmed this viral isolate belonged to lineage B.1. The epidemiology of this case is consistent with those of other early cases before sustained community transmission, which included a travel history outside of Canada., Conclusion: This exercise provides support that local public health pandemic planning was satisfactory and timely., Competing Interests: The authors have nothing to disclose., (Copyright © 2021, Association of Medical Microbiology and Infectious Disease Canada (AMMI Canada).)

This study evaluated a hospital influenza immunization program for inpatients aged ≥65 years during the 2008-2009 influenza season. Of the 520 inpatients in this age group, 45.0% had documented eligibility screening and 23.1% received vaccination in the hospital. Staff and physicians participating in interviews felt that standardizing processes and improving documentation could help enhance the existing program., (Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.)