Prevalence and Correlates of Frailty Among Older Adults Living With HIV in the CHANGE HIV Cohort.

BACKGROUND: Advancements in treatment have resulted in improved survival among people living with HIV. However, additional years of life are not necessarily spent in good health, as frailty tends to develop at a younger age among people living with HIV. We set out to examine the prevalence of frailty and its correlates among older adults living with HIV in Canada, with a primary interest in nadir CD4 count. METHODS: We performed a cross-sectional analysis of the Correlates of Healthy Aging in Geriatric HIV (CHANGE HIV) study, a Canadian cohort of people living with HIV aged 65 years or older. Participants were assessed using the Fried Frailty Phenotype at cohort entry, and those meeting ≥3 criteria were characterized as frail. We used Poisson regression with robust standard errors to estimate the association between nadir CD4 count and frailty, as well as age, gender, time since HIV diagnosis, comorbidities, marital status, and loneliness. RESULTS: Among 439 participants included in this analysis (median age 69 years, interquartile ranges 67-73), prevalence of frailty was 16.6%. Frailty was not associated with nadir CD4 count. Not being in a relationship (aRR 2.09, 95% CI 1.01 to 4.30) and greater degree of loneliness (aRR 1.25 per 10 point increase on UCLA loneliness scale, 95% CI 1.09 to 1.44) were associated with frailty. CONCLUSIONS: Frailty occurred in 16.6% of older adults living with HIV in this cohort. While nadir CD4 count did not correlate with frailty, being single and lonely did, highlighting the importance of recognizing and addressing these social vulnerabilities among people aging with HIV.

The first case of Mpox infection in Iran during the 2022 outbreak.

INTRODUCTION: The unexpected outbreak of human Mpox infection beginning in some European countries that were non-endemic for Mpox stunned the world during the Coronavirus Disease 2019 (COVID-19) pandemic in May 2022. The re-emerging Mpox outbreak, which has a greater capacity for human-to-human transmission, was mainly due to traveling. In this paper, we describe the first case of the disease was observed in an Iranian woman infected by her husband who had a history of traveling to Canada. CASE REPORT: The 34-year-old woman had flu-like syndrome with some skin rashes on her hand, finger, and arm. No antivirals were prescribed in this case, and supportive care was used to help her recover. RT-PCR and Sanger sequencing were used to analyze the sample from the oropharyngeal swab and the rash, and the results confirmed the Mpox infection. CONCLUSIONS: The risk of infectious disease outbreaks after COVID-19, such as Mpox, is of great importance, and health systems should be vigilant for timely identification and preparedness.

Characterizing visual field loss from past mercury exposure in an Indigenous riverine community (Grassy Narrows First Nation, Canada): a cluster-based approach.

BACKGROUND: Between 1962 and 1975, a chlor-alkali plant in Canada discharged approximately 9 metric tons of mercury (Hg) into the Wabigoon River. Over the following decades, biomarkers of Hg exposure of persons from Grassy Narrows First Nation (Asubpeeschoseewagong Anishinabek), located downriver from the discharge, reflected Hg concentrations in fish. Hg exposure is known to target the calcarine fissure, resulting in visual field (VF) loss. Most studies and clinical reports focus solely on peripheral VF loss; little is known about the impact of Hg on the central and paracentral portions. The present study sought to characterize the patterns of VF loss with respect to past and current Hg. METHODS: A 28-year hair-Hg (HHg) database, created from a 1970-97 government biomonitoring program, served to select study participants with ≥ 4 year-based HHg measurements (n = 81). Blood-Hg was assessed for current exposure. Light sensitivity thresholds across the VF were analyzed monocularly, using a Humphrey Field Analyzer (HFA). Following post-hoc exclusions, based on HFA interpretation indices, 65 participants were retained. Both eyes were combined for analyses (n = 130 eyes). Unsupervised hierarchical clustering of HFA plot data was used to identify patterns of VF loss. A series of mixed effects models (MEM) were performed to test the associations for current Hg exposure with respect to HFA interpretation indices and clusters, as well as for longitudinal past Hg exposure. RESULTS: The clustering approach decomposed the light sensitivity deficits into 5 concentric clusters, with greatest loss in the peripheral clusters. No relation was observed between any of the cluster scores and current blood-Hg. VF deficits increased with past Hg exposure. Longitudinal MEM showed that HHg was significantly (p < 0.05) associated with all peripheral, paracentral, and central cluster scores, as well as with HFA interpretation indices. CONCLUSIONS: Past Hg exposure in Grassy Narrows First Nation was associated with present day VF loss. The cluster-based location-specific approach identified patterns of VF loss associated with long-term Hg exposure, in both the peripheral and the central areas. The functional implications of this type of visual loss should be investigated.

Faltering mortality improvements at young-middle ages in high-income English-speaking countries.

BACKGROUND: Before the COVID-19 pandemic, stagnating life expectancy trends were reported in some high-income countries (HICs). Despite previous evidence from country-specific studies, there is a lack of comparative research that provides a broader perspective and challenges existing assumptions. This study aims to examine longevity trends and patterns in six English-speaking countries (Australia, Canada, Ireland, New Zealand, United Kingdom, United States) by combining period and cohort perspectives and to compare them with other HICs. METHODS: Using data from the Human Mortality and World Health Organization Mortality Databases, we estimated partial life expectancy, lifespan inequality and cohort survival differences for 1970-2021, as well as the contribution of causes of death to the gap in life expectancy between English-speaking countries and the average for other HICs in 2017-19. RESULTS: In the pre-pandemic period, the increase in life expectancy slowed in all English-speaking countries, except Ireland, mainly due to stagnating or rising mortality at young-middle ages. Relative to other HICs, those born in Anglophone countries since the 1970s experienced relative survival disadvantage, largely attributable to injuries (mainly suicides) and substance-related mortality (mainly poisonings). In contrast, older cohorts enjoyed advantages for females in Australia and Canada and for males in all English-speaking countries except the United States. CONCLUSIONS: Although future gains in life expectancy in wealthy societies will increasingly depend on reducing mortality at older ages, adverse health trends at younger ages are a cause for concern. This emerging and avoidable threat to health equity in English-speaking countries should be the focus of further research and policy action.

Psychological well-being and its associations with sociodemographic characteristics, physical health, substance use and other mental health outcomes among adults in Canada. / Le bien-être psychologique et ses associations avec les caractéristiques sociodémographiques, la santé physique, la consommation de substances et d'autres composantes de la santé mentale chez les adultes au Canada.

INTRODUCTION: Psychological well-being (PWB) is an important component of positive mental health (PMH) and an asset for population health. This study examined correlates of PWB among community-dwelling adults (18+ years) in the 10 Canadian provinces. METHODS: Using data from the 2019 Canadian Community Health Survey Rapid Response on PMH, we conducted linear regression analyses with sociodemographic, mental health, physical health and substance use variables as predictors of PWB. PWB was measured using six questions from the Mental Health Continuum-Short Form, which asked about feelings of self-acceptance, personal growth, environmental mastery, autonomy, positive relations and purpose in life during the past month. RESULTS: In unadjusted and adjusted analyses, older age, being married or in a commonlaw relationship and having a BMI in the overweight category (25.00-29.99) were associated with higher PWB, while reporting a mood disorder, anxiety disorder, high perceived life stress, engaging in heavy episodic drinking and frequent cannabis use were associated with lower PWB. Sex, having children living at home, immigrant status, racialized group membership, educational attainment, household income tertile, having a BMI in the obese category (≥30.00), major chronic disease and smoking status were not significantly associated with PWB. CONCLUSION: This research identifies sociodemographic, mental health, physical health and substance use factors associated with PWB among adults in Canada. These findings highlight groups and characteristics that could be the focus of future research to promote PMH.

Assessing the impact of the COVID-19 pandemic on the mental health-related hospitalization rate of youth in Canada: an interrupted time series analysis. / Évaluation de l'effet de la pandémie de COVID-19 sur le taux d'hospitalisation pour des raisons de santé mentale chez les jeunes au Canada : analyse de séries chronologiques interrompues.

INTRODUCTION: This study evaluated the effect of the COVID-19 pandemic on temporal trends in mental health and addiction-related inpatient hospitalization rates among youth (aged 10-17 years) in Canadian provinces and territories (excluding Quebec) from 1 April 2018 to 5 March 2022. METHODS: We conducted an interrupted time series analysis across three periods: T0 (pre-pandemic: 1 April 2018 to 15 March 2020); T1 (early pandemic: 15 March 2020 to 5 July 2020); and T2 (later pandemic: 6 July 2020 to 5 March 2022). RESULTS: Pre-pandemic mental health and addiction-related hospitalization rates had significant regional variability, with weekly rates from 6.27 to 85.59 events per 100 000 persons in Manitoba and the territories combined, respectively. During T1, the national (excluding Quebec) weekly hospitalization rate decreased from a pre-pandemic level of 12.82 (95% CI: 12.14 to 13.50) to 5.11 (95% CI: 3.80 to 6.41) events per 100 000 persons. There was no statistically significant change in the mental health and addiction- related hospitalization rate across provinces and territories in T2 compared to T0. However, there was a significant increase in the rate of self-harm-related hospitalizations among females Canada-wide and in most provinces during this period. CONCLUSION: Although several Canadian studies have reported increases in mental health and addiction-related outpatient and emergency department visits among youth during the COVID-19 pandemic, this did not correspond to an increase in the inpatient hospital burden, with the notable exception of self-harm among young females.

Children's self-reported exposure to sugary beverage advertisements and association with intake across six countries before and during the COVID-19 pandemic: a repeat cross-sectional study.

BACKGROUND: Children's exposure to sugary beverage advertising may have changed during the COVID-19 pandemic due to shifts in media habits, which could subsequently have influenced intake. This study aimed to examine: 1) children's frequency and setting of exposure to advertisements of sugary beverages in six countries before and during the COVID-19 pandemic; 2) the association between exposure to sugary beverage advertisements and intake. METHODS: Children aged 10-17 years (n = 28,908) in Australia, Canada, Chile, Mexico, the United Kingdom (UK) and the United States (US) completed online surveys in 2019, 2020 and 2021 as part of the International Food Policy Study using a repeat cross-sectional study design. Respondents self-reported frequency and setting of exposure to sugary beverage advertisements, location of school classes (in-person/online, 2020-2021 only), screen time, and sugary beverage intake. Adjusted weighted logistic and negative binomial regression models stratified by country examined associations between year and reported sugary beverage advertising exposure, and associations between sugary beverage advertising exposure and intake. Differences in reported advertising exposure between students taking online or in-person school classes were explored. RESULTS: Self-reported exposure to advertisements for sugary beverages at least weekly was relatively stable across years within countries, with differences in settings of exposure. Exposure to sugary beverage advertisements increased on digital media independently of screen time from 2019 to 2021 in Australia, Canada, the UK and US, with a concomitant decrease in exposure in retail settings in all countries except the UK. In Australia and the UK, children attending all classes online were more likely to report at least weekly (vs less than once a week) exposure to sugary beverage advertisements, and children attending all classes online were more likely to report exposure to advertisements on digital media and in other settings (e.g., billboard, magazines) compared to children attending in-person classes in Australia, Canada and the UK. Exposure to sugary beverage advertisements at least weekly (IRR = 1.12,99%CI:1.09-1.15) and in each of the settings was associated with sugary beverage intake. CONCLUSIONS: Exposure to digital advertisements for sugary beverages increased from 2019 to 2021 in most countries, and exposure was associated with sugary beverage intake. Reducing children's exposure to advertising of less healthy foods, including on digital media, may reduce sugary beverage intake.

Prevalence and Predictors of Inflammatory Arthritis in Hidradenitis Suppurativa.

Hidradenitis Suppurativa (HS) is a chronic, debilitating, auto-inflammatory condition often associated with inflammatory arthritis, significantly impacting patients' quality of life. Early diagnosis of both conditions is crucial for optimal management. The objective of this study was to determine the prevalence and factors associated with the development of inflammatory arthritis among HS patients. A cross-sectional study was conducted between November 2021 and February 2023 at an academic dermatology centre in Canada. Adult patients with HS were consecutively sampled, and 52 patients consented to participate and completed assessments. Variables examined included age, sex, HS severity, treatment, ethnicity, family history, lifestyle factors and comorbidities. The main outcomes were rheumatologist-confirmed inflammatory arthritis diagnosis and associated risk factors. Among 52 patients (24 males, 28 females; mean age: 37.4 years), 12 had inflammatory arthritis. Multivariate analysis revealed that Blacks (OR = 0.10, p < 0.001, CI: 0.026-0.343) and Asians (OR = 0.02, p < 0.001, CI: 0.005-0.109) had lower inflammatory arthritis odds compared to Whites. Every 1-year increase in age at HS onset correlated with a 1.17-fold increase in the odds of developing inflammatory arthritis (OR: 1.17, p < 0.001, CI: 1.12-1.24). Smoking (OR = 0.01, p < 0.001, CI: 0.002-0.49), hypertension (OR: 0.23, p = 0.04, CI: 0.057-0.930) and depression (OR: 0.12, p < 0.001, CI: 0.041-0.330) reduced inflammatory arthritis odds. White ethnicity and older age at HS onset were positively associated with inflammatory arthritis, while smoking, hypertension and depression were negatively associated. These findings suggest a distinct subset of HS patients with inflammatory arthritis that warrant further prospective studies. This study contributes to the understanding of inflammatory arthritis in HS patients and emphasises the importance of rheumatology referral during dermatologic clinic visits.

Psychological distress among healthcare providers during the COVID-19 pandemic: patterns over time.

BACKGROUND: COVID-19 added to healthcare provider (HCP) distress, but patterns of change remain unclear. This study sought to determine if and how emotional distress varied among HCP between March 28, 2021 and December 1, 2023. METHODS: This longitudinal study was embedded within the 42-month prospective COVID-19 Cohort Study that recruited HCP from four Canadian provinces. Information was collected at enrollment, from annual exposure surveys, and vaccination and illness surveys. The 10-item Kessler Psychological Distress Scale (K10) was completed approximately every six months after March 28, 2021. Linear mixed effects models, specifically random intercept models, were generated to determine the impact of time on emotional distress while accounting for demographic and work-related factors. RESULTS: Between 2021 and 2023, the mean K10 score fell by 3.1 points, indicating decreased distress, but scores increased during periods of high levels of mitigation strategies against transmission of SARS-CoV-2, during winter months, and if taking antidepression, anti-anxiety or anti-insomnia medications. K10 scores were significantly lower for HCP who were male, older, had more children in their household, experienced prior COVID-19 illness(es), and for non-physician but regulated HCP versus nurses. A sensitivity analysis that included only those who had submitted at least five K10 surveys consisted of the factors in the full model excluding previous COVID-19 illness, occupation, and season, after adjustment. Models were also created for K10 anxiety and depression subscales. CONCLUSIONS: K10 scores decreased as the COVID-19 pandemic continued but increased during periods of high mitigation and the winter months. Personal and work-place factors also impacted HCP distress scores. Further research into best practices in distress identification and remediation is warranted to ensure future public health disasters are met with healthcare systems that are able to buffer HCP against short- and long-term mental health issues.

What contributes to a decline in cognitive performance among home care clients? Analysis of interRAI data from across Canada.

BACKGROUND: The current study examined potential risk factors for experiencing a decline on the interRAI Cognitive Performance Scale (CPS). METHODS: This was a retrospective cohort study using secondary data collected with the Resident Assessment Instrument for Home Care (RAI-HC) for all assessments completed in Canada between 2001 and 2020. Eligible home care clients included individuals 65+, with at least two assessments completed within 12 months, and who had a CPS score of zero at baseline (n = 146,187). A decline on the CPS was defined as any increase (i.e., worsening) on the CPS score between the two assessments. RESULTS: The mean age of the sample was 80.6 years (standard deviation = 7.7), 67.9% were female and 44.5% were widowed. At the time of the second assessment, 25.2% experienced a decline on their CPS score. In the final multivariate model, age, having a diagnosis of Alzheimer's dementia/other type of dementia, physical inactivity, and having a caregiver at risk of experiencing burden were the most significant predictors of experiencing the outcome. CONCLUSIONS: Roughly one-quarter of Canadian home care clients experienced a cognitive decline, over an average of seven months. Since there are some modifiable risk factors for this outcome, it is important to identify and flag these factors as early as possible. Early identification of modifiable risk factors allows clinicians to create care plans that can optimize the well-being of the client and their family.

Probabilistic bias analysis for exposure misclassification of household income by neighbourhood in a cohort of individuals with colorectal cancer.

INTRODUCTION: Despite poor agreement, neighbourhood income is used as a proxy for household income, due to a lack of data availability. We quantified misclassification between household and neighbourhood income and demonstrate quantitative bias analysis (QBA) in scenarios where only neighbourhood income is available in assessing income inequalities on colorectal cancer mortality. METHODS: This was a retrospective study of adults with colorectal cancer diagnosed 2006-14 from Statistics Canada's Canadian Census Health and Environment Cohort. Neighbourhood income quintiles from Statistics Canada were used. Census household income quintiles were used to determine bias parameters and confirm results of the QBA. We calculated positive and negative predictive values using multinomial models, adjusting for age, sex and rural residence. Probabilistic QBA was conducted to explore the implication of exposure misclassification when estimating the effect of income on 5-year mortality. RESULTS: We found poor agreement between neighbourhood and household income: positive predictive values ranged from 21% to 37%. The bias-adjusted risk of neighbourhood income on 5-year mortality was similar to the risk of mortality by household income. The bias-adjusted relative risk of the lowest income quintile compared with the highest was 1.42 [95% simulation interval (SI) 1.32-1.53] compared with 1.46 [95% confidence interval (CI) 1.39-1.54] for household income and 1.18 (95% CI 1.12-1.24) for neighbourhood income. CONCLUSION: QBA can be used to estimate adjusted effects of neighbourhood income on mortality which represent household income. The predictive values from our study can be applied to similar cohorts with only neighbourhood income to estimate the effects of household income on cancer mortality.

From BpTRU to OMRON: The impact of changing automated blood pressure measurement devices on adult population estimates of blood pressure and hypertension.

Background: In Cycle 7 (2022), the Canadian Health Measures Survey (CHMS) introduced the OMRON (OM) IntelliSense HEM-907XL blood pressure (BP) monitor after using the BpTRU (BT) BPM-300 BP monitor for six cycles. This study assessed differences between adult BP values measured by both devices and whether equations could be developed to compare BP measurements taken using the two devices. Data and methods: In Cycle 6 (2018 to 2019) of the CHMS, BP was measured using BT and OM devices. Between-device estimates of systolic BP (SBP), diastolic BP (DBP), and hypertension prevalence were compared for 1,072 adults aged 18 to 79 years. Sex, age, body mass index (BMI), and the use of antihypertensive medication were examined in linear regression models to predict SBP and DBP values measured with OM based on those measured with BT. Results: Average SBP measured with OM was 6 millimetres of mercury (mmHg) higher than average SBP measured with BT, and average DBP measured with OM was 2 mmHg lower than DBP measured with BT. Hypertension prevalence based on OM readings was 35.4%, compared with 34.0% based on BT readings. Between-device BP differences varied in magnitude by sex, age group, and BMI category. Average model-predicted estimates of BP were comparable to measured estimates, but predicted values were lower at higher levels of BP. Interpretation: Switching BP monitors will substantively affect population estimates of adult SBP and DBP but may have less impact on estimates of adult hypertension prevalence. The prediction equations proposed in this study can be applied to adult BP data from cycles 1 to 6 of the CHMS for comparison with BP measurements taken in Cycle 7, with some caveats. The impact of changing to the OM monitor in Cycle 7 should be acknowledged when reporting estimates of adult BP based on the CHMS.

Pathogens from salmon aquaculture in relation to conservation of wild Pacific salmon in Canada.

The spread of pathogens from farmed salmon is a conservation concern for wild Pacific salmon in British Columbia (BC), Canada. Three pathogens are prevalent in farmed Atlantic salmon in BC, spill over to wild Pacific salmon, and are linked to negative impacts on wild salmon: Piscine orthoreovirus, Tenacibaculum spp., and sea lice (Lepeophtheirus salmonis). Molecular screening of infectious agents in farmed and wild salmon and environmental DNA highlights a further 4 agents that are likely elevated near salmon farms and 37 that co-occur in wild and farmed salmon. Pathogens likely affect wild salmon indirectly by mediating migration, competition, and predation. Current net-pen aquaculture practices pose these risks to numerous populations of all species of wild salmon in BC, most of which are not covered in Government of Canada science and advisory reports. Climate change, pathogen evolution, and changes to disease management and aquaculture regulations will influence future risks.

Social epidemiology of urban COVID-19 inequalities in Latin America and Canada.

BACKGROUND: The COVID-19 pandemic has spread through pre-existing fault lines in societies, deepening structural barriers faced by precarious workers, low-income populations, and racialized communities in lower income sub-city units. Many studies have quantified the magnitude of inequalities in COVID-19 distribution within cities, but few have taken an international comparative approach to draw inferences on the ways urban epidemics are shaped by social determinants of health. METHODS: Guided by critical epidemiology, this study quantifies sub-city unit-level COVID-19 inequalities across eight of the largest metropolitan areas of Latin America and Canada. Leveraging new open-data sources, we use concentration indices to quantify income- and vulnerability-related inequalities in incidence, test positivity, and deaths over the first 125 weeks of the pandemic between January 2020 and May 2022. RESULTS: Our findings demonstrate that incidence, deaths, and test positivity are all less concentrated in low-income sub-city units than would be expected, with incidence ranging concentration in lower income neighbourhoods in Toronto (CI = -0.07) to concentration in higher income neighbourhoods in Mexico City (CI = 0.33). Drawing on relevant studies and evaluations of data reliability, we conclude that the best available public surveillance data for the largest cities in Latin America are likely not reliable measures of the true COVID-19 disease burden. We also identify recurring trends in the evolution of inequalities across most cities, concluding that higher income sub-city units were frequent early epicentres of COVID-19 transmission across the Latin America and Canada. CONCLUSIONS: Just as critical epidemiology points to individuals biologically embodying the material and social conditions in which we live, it may be just as useful to think of cities reifying their material and social inequities in the form of sub-city unit-level infectious disease inequities. By shifting away from a typical vulnerability-based social determinants of health frame, policymakers could act to redress and reduce externalities stemming from sub-city unit-level income inequality through redistributive and equity-promoting policies to shift the centre of gravity of urban health inequalities before the next infectious disease epidemic occurs.

Combined Exposure to Folate and Lead during Pregnancy and Autistic-Like Behaviors among Canadian Children from the MIREC Pregnancy and Birth Cohort.

BACKGROUND: Folic acid (FA) supplementation may attenuate the associations between gestational exposure to certain chemicals and autism or autistic-like behaviors, but to our knowledge, this has not been assessed for lead. OBJECTIVES: We examined whether the relationship between gestational blood-lead levels (BLLs) and autistic-like behaviors was modified by gestational plasma total folate concentrations, FA supplementation, and maternal methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype. METHODS: We used data from the Maternal-Infant Research on Environmental Chemicals study (2008-2011), a Canadian pregnancy and birth cohort study. Childhood autistic-like behaviors were documented in 601 children 3-4 y of age with the Social Responsiveness Scale-2 (SRS-2), where higher scores denote more autistic-like behaviors. We measured BLLs and plasma total folate concentrations during the first and third trimesters of pregnancy. We also estimated gestational FA supplementation via surveys and genotyped the maternal MTHFR 677C>T single nucleotide polymorphism (SNP). We estimated the confounder-adjusted associations between log2-transformed BLLs and SRS-2 scores by two indicators of folate exposure and maternal MTHFR 677C>T genotype using linear regression. RESULTS: Third-trimester BLLs were associated with increased SRS-2 scores [ßadj=3.3; 95% confidence interval (CI): 1.1, 5.5] among participants with low (<10th percentile), third-trimester, plasma total folate concentrations, but BLL-SRS-2 associations were null (ßadj=-0.3; 95% CI: -1.2, 0.5) among those in the middle category (≥10th and <80th percentiles) (p-interaction <0.001). FA supplementation also attenuated these associations. Both folate indicators modified first-trimester BLL-SRS-2 associations, but to a lesser extent. Third-trimester BLL-SRS-2 associations were slightly stronger among participants who were homozygous for the T (minor) allele of the MTHFR 677C>T SNP (ßadj=0.9; 95% CI: -1.2, 3.1) than those without the T allele (ßadj=-0.3; 95% CI: -1.3, 0.7), but the difference was not statistically significant (p-interaction=0.28). DISCUSSION: Folate may modify the associations between gestational lead exposure and childhood autistic-like behaviors, suggesting that it mitigates the neurotoxic effects of prenatal lead exposure. https://doi.org/10.1289/EHP14479.

Burden of SARS-CoV-2 infection prior to vaccine eligibility among immunocompromised children aged 1-11 years at a pediatric tertiary referral hospital in Toronto, Canada.

SARS-CoV-2 seroprevalence reflects the efficacy of pandemic infection prevention and control measures. We performed anti-spike IgG serological testing on residual sera of children 1-11 years old at a tertiary care referral center between October and November 2021. Immunocompromised patients had the highest SARS-CoV-2 seroprevalence, at 40.5%, compared to 19.3% in non-immunocompromised patients. Targeted infection prevention and public health interventions are warranted for pediatric immunocompromised patients in future pandemics.

Long-Term Exposure to Outdoor Ultrafine Particles and Black Carbon and Effects on Mortality in Montreal and Toronto, Canada.

INTRODUCTION: Numerous studies support an important relationship between long-term exposure to outdoor fine particulate air pollution (PM2.5) and both nonaccidental and cause-specific mortality. Less is known about the long-term health consequences of other traffic pollutants, including ultrafine particles (UFPs, <0.1 µm) and black carbon (BC), which are often present at elevated concentrations in urban areas but are not currently regulated. Knowledge is lacking largely because these pollutants generally are not monitored by governments and vary greatly over small spatial scales, hindering the evaluation of long-term exposures in population-based studies. METHODS: We aimed to estimate associations between long-term exposures to outdoor UFPs and BC and nonaccidental and cause-specific mortality in Canada's two largest cities, Montreal and Toronto. We considered several approaches to exposure assessment: (1) land use regression (LUR) models based on large-scale year-long mobile monitoring campaigns combined with detailed land use and traffic information; (2) machine learning (i.e., convolutional neural networks [CNN]) models trained by combining mobile monitoring data with aerial images; and (3) the combined use of these two approaches. We also examined exposure models with and without backcasting based on historical trends in vehicle emissions (to capture potential trends in pollutant concentrations over time) and with and without accounting for neighborhood-level mobility patterns (based on travel demand surveys). These exposure models were linked to members of the Canadian Census Health and Environment Cohorts (CanCHEC) residing in Montreal or Toronto (including census years 1991, 1996, 2001, and 2006) with mortality follow-up from 2001 (or cohort entry for the 2006 cohort) to 2016. Cox proportional hazard models were used to estimate associations between long-term exposures to outdoor UFPs and BC, adjusting for sociodemographic factors and co-pollutants identified as potential confounding factors. Concentration-response relationships for outdoor UFPs and BC were also examined for nonaccidental and cause-specific mortality using smoothing splines. RESULTS: Our cohort study included approximately 1.5 million people with 174,200 nonaccidental deaths observed during the follow-up period. Combined LUR and machine learning model predictions performed slightly better than LUR models alone and were used as the main exposure models in all epidemiological analyses. Long-term exposures to outdoor UFP number concentrations were consistently positively associated with nonaccidental and cause-specific mortality. Importantly, hazard ratios (HRs) for outdoor UFP number concentrations were sensitive to adjustment for UFP size: UFP size was inversely related to number concentrations and independently associated with mortality, resulting in underestimation of mortality risk for outdoor UFP number concentrations when UFP size was excluded. HRs for outdoor UFP number concentrations were robust to backcasting and mobility weighting but varied slightly in analyses using LUR and machine learning models alone, with stronger associations typically observed for the machine learning models. Associations between outdoor BC concentrations and mortality were generally weak or null, but a positive association was observed for cardiovascular mortality. CONCLUSIONS: Outdoor UFP number concentrations were consistently associated with increased risks of nonaccidental and cause-specific mortality in Montreal and Toronto. Our results suggest that UFP size should be considered in epidemiological analyses of outdoor UFP number concentrations, as excluding size can lead to an underestimation of health risks. Our results suggest that outdoor UFP number concentrations are positively associated with mortality independent of other outdoor air pollutants, including PM2.5 mass concentrations and oxidant gases (i.e., nitrogen dioxide [NO2] and ozone [O3]). As outdoor UFPs are currently unregulated, interventions targeting these pollutants could significantly affect population health.

Inflammatory bowel disease uncovered in fecal immunochemical test positive patients in a Canadian provincial colon cancer screening program.

Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition that usually affects younger adults but has a second incidence peak in the older population. Although diagnosis of IBD is driven by symptoms, some patients are asymptomatic and incidentally discovered while participating in colon screening program (CSP). We aimed to identify the incidence and outcome of IBD in fecal immunochemical test (FIT) positive patients in the British Columbia CSP. We conducted a retrospective chart review of patients who had colonoscopies for positive FIT and were found to have colitis based on endoscopic and histological assessment. Of 93,994 patients who underwent screening colonoscopy for positive FIT between 2009 and 2017, 608 (0.6%) were found to have colitis. From 11 CSP sites, 191 patients met the inclusion criteria. 58 patients (30.4%) were diagnosed with ulcerative colitis, 109 (57.1%) with Crohn's disease (CD), and 24 (12.6%) with IBD unclassified. 124 patients (64.9%) received treatment, of which 34 (17.8%) received biologics and 4 (2.1%) required surgery. Our study demonstrated a clinically significant incidence of IBD, with novel finding of CD predominance, within a Canadian provincial CSP. Further research is needed to guide management of older patients with varying rates of IBD progression after incidental diagnosis.

Potentially Modifiable Dementia Risk Factors in Canada: An Analysis of Canadian Longitudinal Study on Aging with a Multi-Country Comparison.

BACKGROUND: It has been suggested that up to 40% of dementia cases worldwide are associated with modifiable risk factors; however, these estimates are not known in Canada. Furthermore, sleep disturbances, an emerging factor, has not been incorporated into the life-course model of dementia prevention. OBJECTIVE: To estimate the population impact of 12 modifiable risk factors in Canadian adults including sleep disturbances, by sex and age groups, and to compare with other countries. DESIGN: Cross-sectional analysis of Canadian Longitudinal Study on Aging baseline data. SETTING: Community. PARTICIPANTS: 30,097 adults aged 45 years and older. MEASUREMMENTS: Prevalence and Population Attributable Fractions (PAFs) associated with less education, hearing loss, traumatic brain injury, hypertension, excessive alcohol, obesity, smoking, depression, social isolation, physical inactivity, diabetes, and sleep disturbances. RESULTS: The risk factors with the largest PAF were later life physical inactivity (10.2%; 95% CI, 6.8% to 13%), midlife hearing loss (6.5%; 3.7% to 9.3%), midlife obesity (6.4%; 4.1% to 7.7%), and midlife hypertension (6.2%; 2.7% to 9.3%). The PAF of later life sleep disturbances was 3.0% (95% CI, 1.8% to 3.8%). The 12 risk factors accounted for 51.9% (32.2% to 68.0%) of dementia among men and 52.4% (32.5% to 68.7%) among women. Overall, the combined PAF of all risk factors was 49.2% (31.1% to 64.9%), and it increased with age. CONCLUSION: Nearly up to 50% of dementia cases in Canada are attributable to 12 modifiable risk factors across the lifespan. Canadian risk reduction strategies should prioritize targeting physical inactivity, hearing loss, obesity, and hypertension.

"It's not just about you": International students' vulnerabilities and capacities during the first phase of the COVID-19 pandemic in Canada.

In Canada, the COVID-19 pandemic was initially characterized by emergency government responses that disrupted daily life, especially for marginalized groups. This study explored the vulnerabilities and capacities of international students studying at a university in Calgary, Canada during the first phase of the pandemic. Guided by the Capacities and Vulnerabilities Analysis framework, we thematically analyzed 11 semi-structured interviews with international students. We found that material vulnerabilities included balancing finances, housing conditions, lack of information, food inaccessibility, reliance on public transport, and poor mental health, social vulnerabilities included lack of social support, culture shock, and racism, and attitudinal vulnerabilities included "nowhere to go", feeling like a burden, and perception of Canada as safe. Material capacities included financial support, knowledge about pandemic, and mental health supports, social capacities included local social support and multilingualism, and attitudinal capacities included resilience, religious and spiritual beliefs, "it's not just about you", and reflexivity. We found overlapping and complex relationships between vulnerabilities and capacities, indicating that while international students' vulnerabilities were exacerbated and introduced challenges during the pandemic, students uniquely leveraged their capacities to offset and recover from challenges. Findings from this study may be informative for stakeholders involved in disaster responses, especially universities and governments, to support international students' capacities and address their vulnerabilities.