COVID-19 outcome trends by vaccination status in Canada, December 2020-January 2022.

Background: The coronavirus disease 2019 (COVID-19) pandemic in Canada has evolved rapidly. Since late 2020, COVID-19 vaccines have been relied on to protect against severe outcomes in the presence of circulating variants of concern (VOC). Objective: This surveillance report provides a retrospective descriptive analysis of national trends in COVID-19 cases and severe outcomes by vaccination status, contextualizing trends against case demographics and circulating VOCs, from December 2020 to January 2022. Methods: Case and vaccination coverage surveillance data were obtained from the National COVID-19 Case Dataset and the Canadian COVID-19 Vaccination Coverage Surveillance System for 12 of 13 provinces and territories. Descriptive analyses were produced to describe trends over time among individuals aged 12 years and older by COVID-19 outcome, vaccination status, and demographics. Age-standardized and age-stratified incidence rates and incidence rate ratios were computed for cases, hospitalizations, and deaths. Results: From mid to late-2021, incidence rates for cases and severe outcomes were consistently lowest among those with a completed primary series and highest among those who were unvaccinated. Unvaccinated individuals were much more likely to be hospitalized or to die compared to those with a completed primary series in all variant periods. Age-specific rates of severe outcomes were consistently highest among those aged 80 years and older across all vaccination statuses. Conclusion: Vaccination remains one of the most important public health interventions, particularly among older adults, to protect against COVID-19 severe outcomes as the pandemic evolves. Routine monitoring of COVID-19 outcomes by vaccination status can identify changes in COVID-19 epidemiology and inform public health action and policy.

Canadian COVID-19 Outbreak Surveillance System: implementation of national surveillance during a global pandemic.

SETTING: Early in the SARS-CoV-2 pandemic, the need to develop systematic outbreak surveillance at the national level to monitor trends in SARS-CoV-2 outbreaks was identified as a priority for the Public Health Agency of Canada (PHAC). The Canadian COVID-19 Outbreak Surveillance System (CCOSS) was established to monitor the frequency and severity of SARS-CoV-2 outbreaks across various community settings. INTERVENTION: PHAC engaged with provincial/territorial partners in May 2020 to develop goals and key data elements for CCOSS. In January 2021, provincial/territorial partners began submitting cumulative outbreak line lists on a weekly basis. OUTCOMES: Eight provincial and territorial partners, representing 93% of the population, submit outbreak data on the number of cases and severity indicators (hospitalizations and deaths) for 24 outbreak settings to CCOSS. Outbreak data can be integrated with national case data to supply information on case demographics, clinical outcomes, vaccination status, and variant lineages. Data aggregated to the national level are used to conduct analyses and report on outbreak trends. Evidence from CCOSS analyses has been useful in supporting provincial/territorial outbreak investigations, informing policy recommendations, and monitoring the impact of public health measures (vaccination, closures) in specific outbreak settings. IMPLICATIONS: The development of a SARS-CoV-2 outbreak surveillance system complemented case-based surveillance and furthered the understanding of epidemiological trends. Further efforts are required to better understand SARS-CoV-2 outbreaks for Indigenous populations and other priority populations, as well as create linkages between genomic and epidemiological data. As SARS-CoV-2 outbreak surveillance enhanced case surveillance, outbreak surveillance should be a priority for emerging public health threats.

RéSUMé: CONTEXTE: Au début de la pandémie de SRAS-CoV-2, l'Agence de la santé publique du Canada (ASPC) a déterminé comme priorité la nécessité de développer un système de surveillance systématique des éclosions à l'échelle nationale afin de suivre les tendances des éclosions de SRAS-CoV-2. Le système canadien de surveillance des éclosions de COVID-19 (SCSEC) a été établi pour surveiller la fréquence et la gravité des éclosions de SRAS-CoV-2 dans différents milieux communautaires. INTERVENTION: L'ASPC s'est engagée avec les partenaires provinciaux et territoriaux en mai 2020 pour élaborer des objectifs et des éléments de données clés pour le SCSEC. En janvier 2021, les partenaires provinciaux et territoriaux ont commencé à transmettre des listes d'éclosions cumulatives hebdomadaires. RéSULTATS: Huit partenaires provinciaux et territoriaux, représentant 93 % de la population, transmettent au SCSEC des données sur les éclosions sur le nombre de cas et les indicateurs de gravité (les hospitalisations et les décès) pour 24 types de milieux. Les données sur les éclosions peuvent être intégrées avec les données nationales sur les cas pour obtenir des informations sur la démographie des cas, les résultats cliniques, le statut vaccinal et les lignées de variants. Les données agrégées à l'échelle nationale sont utilisées pour effectuer des analyses et faire rapport des tendances sur les éclosions. Les résultats des analyses du SCSEC ont été utiles pour soutenir les enquêtes provinciales/territoriales sur les éclosions, informer les recommandations politiques et surveiller l'impact des mesures de santé publique (la vaccination, les fermetures) dans des milieux d'éclosions spécifiques. IMPLICATIONS: Le développement d'un système de surveillance des éclosions de SRAS-CoV-2 a permis de complémenter la surveillance des cas et d'approfondir notre compréhension des tendances épidémiologiques. Des efforts supplémentaires sont nécessaires pour mieux comprendre les éclosions de SRAS-CoV-2 chez les populations autochtones et d'autres populations minoritaires, ainsi que pour créer des liens entre les données génomiques et les données épidémiologiques. Comme la surveillance des éclosions de SRAS-CoV-2 a enrichi la surveillance des cas, la surveillance des éclosions devrait être une priorité pour les menaces émergentes pour la santé publique.

COVID-19 outbreak trends in Canada, 2021.

Background: In January 2021, the Public Health Agency of Canada launched an outbreak surveillance system, the Canadian COVID-19 Outbreak Surveillance System (CCOSS), with the goal of monitoring incidence and severity of coronavirus disease 2019 (COVID-19) outbreaks across various community settings and complementing case surveillance. Methods: Seven provinces were included in this report; these provinces submitted weekly cumulative COVID-19 outbreak line lists to CCOSS in 2021. Data includes administrative variables (e.g. date outbreak declared, date outbreak declared over, outbreak identifier), 24 outbreak settings, and number of confirmed cases and outcomes (hospitalization, death). Descriptive analyses for COVID-19 outbreaks across Canada from January 3, 2021, to January 1, 2022, were performed examining trends over time, severity, and outbreak size. Results: Incidence of outbreaks followed similar trends to case incidence. Outbreaks were most common in school and childcare settings (39%) and industrial/agricultural settings (21%). Outbreak size ranged from 2 to 639 cases per outbreak; the median size was four cases per outbreak. Correctional facilities had the largest median outbreak size with 18 cases per outbreak, followed by long-term care facilities with 10 cases per outbreak. During periods of high case incidence, outbreaks may be under-ascertained due to limited public health capacity, or reporting may be biased towards high-risk settings prioritized for testing. Outbreaks reported to CCOSS were dominated by jurisdictions with the largest populations. Conclusion: The trends illustrate that COVID-19 outbreaks in 2021 were reported most frequently in community settings such as schools; however, the largest outbreaks occurred in congregate living settings. The information gathered from outbreak surveillance complemented case incidence trends and furthered understanding of COVID-19 in Canada.

Calcium exacerbates the inhibitory effects of phytic acid on zinc bioavailability in rats.

BACKGROUND: Complementary feeding of breastfed infants with foods high in bioavailable zinc (Zn) can help meet physiological requirements for Zn. Some infant cereals contain high concentrations of phytic acid (PA) and calcium (Ca) that may reduce absorbable Zn. OBJECTIVES: This study measured PA, Zn and Ca concentrations in selected infant cereals sold in Canada and investigated the effects of dietary PA and Ca at concentrations present in infant cereals on Zn bioavailability in rats. METHODS AND RESULTS: Male Sprague-Dawley rats (36-day old) were fed a control diet containing normal Zn (29.1 mg/kg) and Ca (4.95 g/kg) or six test diets (n = 12/diet group). Test diets were low in Zn (8.91-9.74 mg/kg) and contained low (2.16-2.17 g/kg), normal (5.00-5.11 g/kg) or high (14.6-14.9 g/kg) Ca without or with added PA (8 g/kg). After 2 weeks, rats were killed and Zn status of the rats was assessed. PA, Zn and Ca concentrations in infant cereals (n = 20) differed widely. PA concentrations ranged from undetectable to 16.0 g/kg. Zn and Ca concentrations ranged from 7.0-29.1 mg/kg and 0.8-13.4 g/kg, respectively. The [PA]/[Zn] and [PA × Ca]/[Zn] molar ratios in infants cereals with detectable PA (16 of 20 cereals) ranged from 22-75 and 0.9-14.9 mol/kg, respectively, predicting low Zn bioavailability. Body weight, body composition (lean and fat mass), right femur weight and length measurements and Zn concentrations in serum and femur indicated that diets higher in Ca had a more pronounced negative effect on Zn status of rats fed a PA-supplemented diet. Addition of PA to the diet had a greater negative effect on Zn status when Ca concentration in the diet was higher. CONCLUSION: These results show that, in rats, higher concentrations of dietary Ca and PA interact to potentiate a decrease in bioavailable Zn and may suggest lower Zn bioavailability in infant cereals with higher PA and Ca concentrations.

Tuberculosis drug resistance in Canada: 2018.

BACKGROUND: Drug-resistant tuberculosis (TB) is a public health issue of global importance that poses a threat to TB control efforts. Canada conducts nationwide surveillance to monitor emerging drug resistance trends and document progress towards reaching the goal of TB elimination. OBJECTIVE: To describe TB drug resistance trends across Canada from 2008-2018, with a focus on 2018, by drug resistance, geographic and demographic patterns. METHODS: TB drug resistance data are captured through two independent surveillance systems managed by the Public Health Agency of Canada: Canadian Tuberculosis Laboratory Surveillance System (CTBLSS) and the Canadian Tuberculosis Reporting System (CTBRS). Data from these systems were analyzed and descriptive statistics were reported by resistance profile, place of residence (province), age groups, sex and country of birth. RESULTS: In 2018, 1,459 TB isolates underwent drug susceptibility testing, a 4.3% decrease from 2017. Resistance to any first-line drug was reported in 148 isolates (10.1%), compared to 123 (8.1%) in 2017. Of these, 121 were monoresistant, five were polyresistant, 21 were multidrug-resistant tuberculosis (MDR-TB) and one was extensively drug-resistant TB (XDR-TB). Drug resistance was reported in all provinces and territories except Prince Edward Island, Northwest Territories and Yukon. Among individuals younger than 15 years, very little TB drug resistance was detected. Among individuals aged 15 years and older, the distribution of TB drug resistance varied with no discernable trends. The proportion of drug resistance was slightly higher in females than in males. By origin, 10.7% of foreign-born TB cases reported between 2006 and 2016 were drug-resistant. Among the Canadian-born non-Indigenous cases, 9.3% were drug resistant; among Canadian-born Indigenous, 2.4% were drug resistant. CONCLUSION: In 2018, the proportion of isolates with TB drug resistance in Canada remained low and below global averages, with stable drug resistance, both geographically and demographically.