Infection-induced seroconversion and seroprevalence of SARS-CoV-2 among a cohort of children and youth in Montreal, Canada.

The EnCORE study is a prospective serology study of SARS-CoV-2 in a cohort of children from Montreal, Canada. Based on data from our fourth round of data collection (May-October 2022), we estimated SARS-CoV-2 seroprevalence and seroconversion. Using multivariable regression, we identified factors associated with seroconversion. Our results show that previously seronegative children were approximately 9-12 times more likely to seroconvert during the early Omicron-dominant period compared to pre-Omicron rounds. Unlike the pre-Omicron rounds, the adjusted rate of seroconversion among 2- to 4-year-olds was higher than older age groups. As seen previously, higher seroconversion rates were associated with ethnic/racial minority status.

Pre-Omicron seroprevalence, seroconversion, and seroreversion of infection-induced SARS-CoV-2 antibodies among a cohort of children and teenagers in Montréal, Canada.

OBJECTIVES: To use serological testing to assess the pre-Omicron seroprevalence, seroconversion, and seroreversion of infection-induced SARS-CoV-2 antibodies in children and adolescents in Montréal, Canada. DESIGN: This analysis is from a prospective cohort study of children aged 2-17 years (at baseline) that included blood spots for antibody detection. The serostatus of participants was determined by enzyme-linked immunosorbent assays using the receptor-binding domain from the spike protein and the nucleocapsid protein as antigens. We estimated seroprevalence, seroconversion rates, and the likelihood of seroreversion at 6 months and 1 year. RESULTS: The baseline (October 2020 to April 2021) seroprevalence was 5.8% (95% confidence interval [CI] 4.8-7.1), which increased to 10.5% (May to September 2021) and 11.0% (November 2021 to March 2022) for the respective follow-ups (95% CI 8.6-12.7; 95% CI 8.8-13.5). The crude rate of seroconversion over the study period was 12.8 per 100 person-years (95% CI 11.0-14.7). The adjusted hazard rates of seroconversion by child characteristics showed higher rates in children who were female, whose parent identified as a racial or ethnic minority, and in households with incomes in the lowest tercile of our study population. The likelihood of remaining seropositive at 6 months was 68% (95% CI 60-77%) and dropped to 42% (95% CI 32-56%) at 1 year. CONCLUSION: Serological studies continue to provide valuable contributions for infection prevalence estimates and help us better understand the dynamics of antibody levels after infection.

Is nature relatedness associated with better mental health? An exploratory study on Vietnamese university students.

OBJECTIVE: This study aims to examine the relationship between nature relatedness (NR) on subjective positive well-being (life satisfaction) and mental disorders (depression, stress, and anxiety) in Vietnamese university students. PARTICIPANTS: 340 Hue University students voluntarily took part in the survey. METHODS: The Nature Relatedness Scale, Depression, Anxiety, and Stress Scale and Satisfaction with Life Scale were used. Bivariate correlation, single regression, and moderation analysis were conducted to investigate the relationship between NR and the mental health of university students and the moderating role of NR. RESULTS: Higher levels of NR significantly predicted higher levels of life satisfaction but did not significantly predict fewer symptoms of depression, anxiety, and stress. NR significantly moderated the link between life satisfaction and depression, anxiety, and stress. CONCLUSIONS: The findings of this study imply that efforts to enhance students' mental health should include efforts to promote their NR.

Evaluation of Real-life Use of Point-of-care Rapid Antigen Testing for SARS-CoV-2 in Schools (EPOCRATES): a cohort study.

BACKGROUND: SARS-CoV-2 transmission has an impact on education. In this study, we assessed the performance of rapid antigen detection tests (RADTs) versus polymerase chain reaction (PCR) for the diagnosis of SARS-CoV-2 infection in school settings, and RADT use for monitoring exposed contacts. METHODS: In this real-world, prospective observational cohort study, high-school students and staff were recruited from 2 high schools in Montréal, Canada, and followed from Jan. 25 to June 10, 2021. Twenty-five percent of asymptomatic participants were tested weekly by RADT (nasal) and PCR (gargle). Class contacts of cases were tested. Symptomatic participants were tested by RADT (nasal) and PCR (nasal and gargle). The number of cases and outbreaks were compared with those of other high schools in the same area. RESULTS: Overall, 2099 students and 286 school staff members consented to participate. The overall specificity of RADTs varied from 99.8% to 100%, with a lower sensitivity, varying from 28.6% in asymptomatic to 83.3% in symptomatic participants. Secondary cases were identified in 10 of 35 classes. Returning students to school after a 7-day quarantine, with a negative PCR result on days 6-7 after exposure, did not lead to subsequent outbreaks. Of cases for whom the source was known, 37 of 51 (72.5%) were secondary to household transmission, 13 (25.5%) to intraschool transmission, and 1 to community contacts between students in the same school. INTERPRETATION: Rapid antigen detection tests did not perform well compared with PCR in asymptomatic individuals. Reinforcing policies for symptom screening when entering schools and testing symptomatic individuals with RADTs on the spot may avoid subsequent substantial exposures in class. Preprint: medRxiv - doi.org/10.1101/2021.10.13.21264960.

Seroprevalence of SARS-CoV-2 Antibodies Among Children in School and Day Care in Montreal, Canada.

Importance: Quebec prioritized in-person learning after the first wave of the COVID-19 pandemic, with school closures being implemented temporarily in selected schools or in hot-spot areas. Quebec's decision to keep most schools open was controversial, especially in Montreal, which was the epicenter of Canada's first and second waves; therefore, understanding the extent to which children were infected with SARS-CoV-2 provides important information for decisions about school closures. Objective: To estimate the seroprevalence of SARS-CoV-2 antibodies in children and teenagers in 4 neighborhoods of Montreal, Canada. Design, Setting, and Participants: This cohort study (the Enfants et COVID-19: Étude de séroprévalence [EnCORE] study) enrolled a convenience sample of children aged 2 to 17 years between October 22, 2020, and March 22, 2021, in Montreal, Canada. Exposures: Potential exposure to SARS-CoV-2. Main Outcomes and Measures: The main outcome was seroprevalence of SARS-CoV-2 antibodies, collected using dried blood spots (DBSs) and analyzed with a research-based enzyme-linked immunosorbent assay (ELISA). Parents also completed an online questionnaire that included questions on self-reported COVID-19 symptoms and tests, along with sociodemographic questions. Results: This study included 1632 participants who provided a DBS sample from 30 day cares, 22 primary schools, and 11 secondary schools. The mean (SD) age of the children who provided a DBS sample was 9.0 (4.4) years; 801 (49%) were female individuals, with 354 participants (22%) from day cares, 725 (44%) from primary schools, and 553 (34%) from secondary schools. Most parents had at least a bachelor's degree (1228 [75%]), and 210 (13%) self-identified as being a racial or ethnic minority. The mean seroprevalence was 5.8% (95% CI, 4.6%-7.0%) but increased over time from 3.2% (95% CI, 0.7%-5.8%) in October to November 2020 to 8.4% (95% CI, 4.4%-12.4%) in March to April 2021. Of the 95 children with positive SARS-CoV-2 antibody results, 78 (82%) were not tested or tested negative with reverse transcription-polymerase chain reaction (RT-PCR) testing, and all experienced mild (49 [52%]) or no clinical symptoms (46 [48%]). The children of parents who self-identified as belonging to a racial and ethnic minority group were more likely to be seropositive compared with children of White parents (adjusted seroprevalence ratio, 1.9; 95% CI, 1.1-2.6). Conclusions and Relevance: These results provide a benchmark of the seroprevalence status in Canadian children. The findings suggest that there was more transmission occurring in children compared with what was being detected by RT-PCR, although children experienced few or mild symptoms. It will be important to continue monitoring the serological status of children, particularly in the context of new COVID-19 variants of concern and in the absence of mass vaccination campaigns targeting young children.

Making sense of what exactly public health does: a typology of public health interventions.

SETTING: Montréal. INTERVENTION: The lack of common knowledge about what public health does is a hindrance to its recognition and capacity to act. Montréal's regional public health department set an explicit goal to clarify and better communicate its specific contributions when it developed its 2016-2021 action plan. This article briefly describes the efforts made to classify public health practice, introduces a typology of public health interventions and discusses its application and benefits. OUTCOMES: The typology that was developed defines 29 types of interventions grouped into four categories: direct action targeting the population; advocacy (persuading partners to take action); support (helping partners take action); collaboration (taking action with partners). The analysis of Montreal's most recent action plan, completely drafted in terms of the typology, provides an insightful characterization of public health practice. Globally, four out of five interventions target partners (indirect), with more than half falling within the support category. Other indirect interventions are divided almost equally between advocacy and collaboration. Following a rigorous planning process and enforcing the use of the typology also had a significant structuring effect on the organization and its teams and enabled greater synergy with partners from other sectors. IMPLICATIONS: Very few people are familiar with everything public health does, sometimes not even the responsible political decision-makers. This situation poses a threat to the survival of its prevention mission. The typology of public health interventions is an innovative tool that can be used to better inform the public and decision-makers.

Mental health service use and treatment adequacy for anxiety disorders in Canada.

BACKGROUND: This study examined mental health service use, minimal standards of treatment adequacy and correlates of service use and treatment adequacy for anxiety disorders in Canada. METHOD: Data were drawn from the Canadian Community Health Survey: Mental Health and Well-Being (CCHS 1.2, 2002). Respondents (n = 1,803) met criteria for panic disorder, agoraphobia and/or social phobia in the past 12 months. Multiple logistic regression models were used to estimate patterns of associations between respondent characteristics, service use and treatment adequacy. RESULTS: The prevalence of service use for mental health problems in the past 12 months was approximately 36.9% among respondents with anxiety disorders. The rates of minimal standards of treatment adequacy ranged from 36.8% among those consulting exclusively in primary care to 51.5% among those consulting exclusively in specialised mental health services, and reached 79.5% for respondents consulting healthcare professionals in both sectors of care. Correlates of treatment adequacy included age, education level, marital status, urbanicity medical insurance, acceptability of care, comorbid mental disorders and limitations of activities. CONCLUSION: These findings emphasize the need to improve the access to mental health services and the quality of care for individuals with anxiety disorders in primary care.

Guideline concordance of treatment for depressive disorders in Canada.

BACKGROUND: Depression is one of the most prevalent mental health problems worldwide with considerable social and economic burdens. While practice guidelines exist, their adherence is inconsistent in clinical practice. OBJECTIVE: To provide up-to-date national estimates of the adequacy of treatment received by Canadians having suffered a major depressive disorder (MDD) and examine factors associated with this adequacy. To evaluate the impact of different definitions of guideline-concordant treatment on the results. SUBJECTS: Data were drawn from the Canadian Community Health Survey, cycle 1.2: Mental Health and Well-Being (CCHS 1.2), a nationally representative survey conducted in 2002 and targetting persons aged 15 years or older living in private dwellings. In order to calculate the prevalence of treatment adequacy, we used a sample of 1,563 individuals meeting the criteria for MDD in the 12 months preceding the survey. A subset of 831 subjects who reported having used health services for mental health purposes at least once during that time served to identify the factors associated with treatment adequacy. MEASUREMENTS: Four definitions of minimally adequate treatment were considered and covariates were selected according to a well-known behavioral model. The analyses consisted of prevalence estimates and logistic regression models. RESULTS: Among selected subjects, 55% received guideline-concordant treatment according to the Canadian guidelines. Inadequacy was more prevalent in rural settings, for less complex cases, and in the general medical sector. Depending on the definition, prevalence of guideline-concordant treatment ranged between 48 and 71%, and factors associated with guideline-concordant treatment were mainly need factors and sector of care. CONCLUSIONS: A large proportion of people with a depressive disorder do not receive minimally adequate treatment. Improved access to and quality of treatment is required, especially in primary care settings.

Inequalities in breast and cervical cancer screening among urban Mexican women.

OBJECTIVE: To examine the equity of screening for breast and cervical cancer among women aged 50 and over living in Mexico City according to the Andersen behavioural model. METHODS: Logistic regressions were used to analyze the associations of predisposing factors, enabling resources and health needs with mammography and Pap testing among 1323 women aged 50 and over living in Mexico City. The data were taken from SABE, a survey conducted in Latin American and Caribbean cities in 1999-2000. RESULTS: Referring to the previous two years, use of mammography was less frequent (14.8%) than Pap testing (53.7%). Higher education and having private health insurance were associated with receiving both procedures. Being married was associated with receipt of Pap testing, while being unmarried was associated with mammography. Younger women were more likely to receive a Pap test. Other cancer prevention behaviours were strong predictors of mammography and Pap test use. CONCLUSIONS: There are inequities in access to cancer screening services among women aged 50 and over in Mexico. Cancer prevention programs need to implement strategies that guarantee free and accessible services independently of social conditions or type of health insurance. The observed clustering of screening services suggests that packaging screening programs for gynaecological cancer could be used to increase coverage.

Life course socioeconomic disadvantage and cognitive function among the elderly population of seven capitals in Latin America and the Caribbean.

OBJECTIVE: To examine the influence of life course socioeconomic disadvantages (SED) on cognitive function in later life. METHOD: Data originate from a survey of people 60 and older living in seven Latin American and Caribbean cities. Cognitive function was measured with a modified Mini-Mental State Examination and the Pfeffer Scale of Functional Capacity. Homogeneity tests were used to pool data. Associations between cognitive function and SED were evaluated, fitting logistic regressions. RESULTS: Cognitive impairment (CI) prevalence ranged from 0.3% to 6.5% in men and 1.2% to 10.1% in women. Childhood rural living, poor childhood health, illiteracy, housewife or farmer occupation, and insufficient income were associated with CI in all seven cities. The odds of CI increase with cumulative exposure to disadvantages along life course. CONCLUSIONS: Life course SED is related to cognitive function later in life. Difficulty in properly distinguishing cognitive function from test performance remains an issue.

Depressive disorders among young Canadians: associated factors of continuity and discontinuity.

OBJECTIVE: The purpose of this study was to compare potential risk factors of depressive disorders among young Canadians (aged 15-24) to those of older age groups (25-34 and 35-44) and examine the contribution of individual and contextual factors in the continuity and discontinuity of depression. METHODS: Data from the Canadian Community Health Survey--Cycle 1.2 were analyzed to examine the associations between individual, familial, social and environmental factors and the continuity or discontinuity of depressive disorders among young Canadians. The sample consisted of 5,673 Canadians aged 15-24, 5,830 aged 25-34 and 7,830 aged 35-44. Youths were also categorized according to the type of cases: non-case, new case, case in remission or long-lasting case. RESULTS: Among Canadian youth, 10.2% had suffered from depression during their lifetime. Social support was the only factor distinguishing the youngest age group from the others regarding depression. Compared to older age groups, stress levels were notably higher for young people. The combination of social network, social support and stress levels strongly distinguished between the long-term cases and the non-cases among youths. Weak feeling of community cohesion was also related to new cases of depression and could contribute to their beginnings. CONCLUSIONS: Potential targets for preventive measures lie in the contextual and social influences of youth; particularly what impacts stress levels, social support and social networks. Studying processes of continuity and discontinuity contribute to identifying distinct profiles of onset, recurrence or remission of depression that may point to avenues for prevention and early intervention.

Correlates of depressive and anxiety disorders among young Canadians.

OBJECTIVE: The current study presents data on the prevalence of depressive and anxiety disorders in the Canadian population aged between 15 and 24 years and examines their potential correlates. METHODS: The study is based on the 2002 Canadian Community Health Survey: Mental Health and Well-Being (CCHS 1.2). This survey was administered to a representative sample of 36,984 Canadians. A subsample of 5673 Canadians aged between 15 and 24 years was available for the analyses. We used descriptive analyses to calculate lifetime and 12-month prevalence of depressive and anxiety disorders, and we used logistic regressions to measure odds ratios. RESULTS: Among Canadian youths, 10.2% had suffered from depressive disorders during their lifetime, whereas 12.1% had suffered from anxiety disorders. For 12-month prevalence, the rates were 6.4% and 6.5% for depressive and anxiety disorders, respectively. Depressive disorders were more frequent among youth aged 20 to 24 years and among those no longer in school. Both disorders were more common among women and people under extreme stress. CONCLUSIONS: The prevalence rates found are comparable with other studies, and most of the correlates are concordant with the literature. Results indicate that there is a turning point for depression between late adolescence and adulthood that could be crucial for intervention planning.