Seroprevalence, seroconversion, and seroreversion of infection-induced SARS-CoV-2 antibodies among a cohort of children and adolescents in Montreal, Canada (preprint)

Importance: Repeated serological testing for SARS-CoV-2 allows the monitoring of antibody dynamics in populations, including detecting infections that are missed by RT-PCR or antigen testing. Understanding the factors associated with seroconversion and seroreversion as well as the duration of infection-induced antibodies can also inform public health recommendations regarding disease prevention and mitigation efforts. Objective: To use serological testing to assess the prevalence, seroconversion, and seroreversion of infection-induced SARS-CoV-2 antibodies in children and adolescents in Montreal, Canada. Design: This analysis reports on three rounds of data collection from a prospective cohort study (Enfants et COVID-19: Etude de seroprevalence [EnCORE]). The study rounds occurred as follows: Round 1 October 2020-March 2021, Round 2 May to July 2021, and Round 3 November 2021 to January 2022. Most Round 3 samples were collected prior to the spread of the Omicron BA.1 variant in Quebec. Setting: Population-based sample. Participants: Children and adolescents aged 2 to 17 years in Montreal, Canada. Exposure: Potential exposure to SARS-CoV-2. Main Outcomes and Measures: Participants provided dried blood spots (DBS) for antibody detection and parents completed online questionnaires for sociodemographics and COVID-19 symptoms and testing history. The serostatus of participants was determined by enzyme-linked immunosorbent assays (ELISAs) using the receptor-binding domain (RBD) from the spike protein and the nucleocapsid protein (N) as antigens. We estimated seroprevalence for each round of data collection and by participant and household characteristics. Seroconversion rates were calculated as were the likelihoods of remaining seropositive at six months and one year. Results: The study included DBS samples from 1 632, 936, and 723 participants in the first, second, and third rounds of data collection, respectively. The baseline seroprevalence was 5.8% (95% CI 4.8-7.1), which increased to 10.5% and 10.9% for the respective follow-ups (95% CI 8.6-12.7; 95% CI 8.8-13.5). The overall average crude rate of seroconversion over the study period was 12.7 per 100 person-years (95% CI 10.9-14.5). Adjusted hazard rates of seroconversion by child and household characteristics showed higher rates in children who were female, whose parent identified as a racial or ethnic minority, and in households with incomes less than 100K. The likelihood of remaining seropositive at six months was 67% (95% CI 59-76) and dropped to 19% (95% CI 11%-33%) at one year. Conclusions and Relevance: The data reported here provide estimates of pre-Omicron seroprevalence, seroconversion rates and time to seroreversion in a population-based cohort of children and adolescents. Serological studies continue to provide valuable contributions for infection prevalence estimates and help us better understand the dynamics of antibody levels following infection. Continued study of seroconversion and seroreversion can inform public health recommendations such as COVID-19 vaccination and booster schedules.

Financial issues in times of a COVID-19 pandemic in a tertiary hospital in Mali (preprint)

Background Health systems in many West African countries have suffered due to low public spending on health. Further, the requirement for high out-of-pocket payments by healthcare users accessing care has raised concerns about equitable access to COVID-19-related services. This study examines how the functioning of healthcare providers during the COVID-19 pandemic was affected by the government financing response to the pandemic, which itself is underpinned by existing healthcare financing systems. The analysis focuses on the key actor groups in healthcare service delivery, both providers and recipients of healthcare services at a tertiary hospital in Mali. Methods The study applied a single case study design. The case study was undertaken at a tertiary hospital in the Malian capital, Bamako, during the 1st and 2nd waves of the COVID-19 pandemic. Data were gathered through a total of 51 in-depth interviews with hospital staff, participatory observation, and the review of media articles and hospital financial records. Thematic analysis using pre-coded themes was applied. The study results were presented to hospital management to confirm the validity of the data analysis. Results The study highlighted the disruptions experienced by hospital managers, human resources for health and patients in Mali during the early stages of the pandemic. While the government aimed to support universal access to COVID-19-related services, efforts were undermined by issues associated with complex public financing procedures and the hospital experienced long delays in the government transfer of funds. Additionally, the hospital suffered a decrease in revenue during the early stages of the pandemic. The challenges faced by the hospitals led to the delays in promised bonuses and payment of salaries to individual hospital staff members, which created potential for unfair treatment of patients. Conclusions Preexistent issues in healthcare financing and governance constrained the effective management of COVID-19 related services and created confusion at the front-line of healthcare service delivery. There is a need to reflect on hospital operations and human resource management in Mali and learn from the experience of COVID-19 to create an environment in which hospitals and their staff can deliver quality services and where patients can access healthcare services in times of need.

'It felt like building a plane while in flight': The Consideration of Social Inequities in Health in the Design of a Contact-Tracing Program for COVID-19 in Montréal (preprint)

Background: In Canada and globally, the COVID-19 pandemic has increased social inequities in health (SIH), furthering the vulnerability of certain groups and communities. Contact tracing is a cornerstone intervention with COVID-19 prevention and control programs. The aim of this study was to describe if and how SIH were considered during the design of the COVID-19 contact tracing program in Montréal.Methods: A qualitative case study was carried out in Montréal, based on a “bricolage” conceptual framework describing the consideration for SIH in intervention and policy design. Qualitative data were collected using semi-structured interviews with 16 public health practitioners, recruited using both purposive and snowball sampling. Data was analyzed using thematic analysis, both inductively and deductively.Results: Results showed that SIH were not considered during the design of contract tracing in Montréal, which the respondents thought was due to the crisis nature of the situation. Public health practitioners deplored the Québec government’s lack of will to integrate SIH into the public health response, as well as the lack of preparedness to pandemics.Conclusions: Considering these findings, prior to designing public health interventions, decision-makers need to have a common vision of SIH, allowing to conceptualize and consider SIH better in the future.

Evaluation of real-life use of Point-Of-Care Rapid Antigen TEsting for SARS-CoV-2 in schools for outbreak control (EPOCRATES) (preprint)

AbstractO_ST_ABSBackgroundC_ST_ABSWe evaluated the use of rapid antigen detection tests (RADT) for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in school settings to determine RADTs performance compared to PCR. MethodsIn this real-world, prospective observational cohort study, high-school students and staff were recruited from two high-schools in Montreal (Canada) and followed from January 25th to June 10th, 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 to other high schools in the same area. ResultsOverall, 2,099 students and 286 school staff members consented to participate. The overall RADTs specificity 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 on D6-7 after exposure, did not lead to subsequent outbreaks. Of cases for whom the source was known, 37 of 57 (72.5%) were secondary to household transmission, 13 (25%) to intra-school transmission and one to community contacts between students in the same school. ConclusionRADT did not perform well as a screening tool in asymptomatic individuals. Reinforcing policies for symptom screening when entering schools and testing symptomatic individuals with RADT on the spot may avoid subsequent significant exposures in class. Table of Contents SummaryRapid antigen tests were compared to standard PCR to diagnose SARS-CoV-2 infections in high-school students. They performed better in symptomatic individuals. Whats Known on This SubjectRapid antigen detection tests (RADT) are often used to diagnose respiratory pathogens at the point-of-care. Their performance characteristics vary, but they usually have high specificity and moderate sensitivity compared with PCR. What This Study AddsRADT sensitivity ranged from 28.6% in asymptomatic individuals to 83.3% in symptomatic individuals. Return to school after 7 days of quarantine was safe in exposed students. Secondary cases were identified in 28% of classes with an index case.

Considering Social Inequalities in Health in Large-Scale Testing for Covid-19 in Montreal: A Qualitative Case Study (preprint)

Evidence shows that COVID-19 is exacerbating social inequalities in health (SIH). The aim of this qualitative study was to assess how SIH were considered in the design of large-scale COVID-19 testing programs in Montreal (Quebec, Canada). We conducted semi-structured interviews with 19 stakeholders involved in planning large-scale testing or working with vulnerable populations during the pandemic. We developed interview guides and a codebook using literature on policy design and planning, and analysed data deductively and inductively using thematic analysis in NVivo. Findings suggest that large-scale COVID-19 testing in Montreal did not initially consider SIH in their planning phases. However, adaptations were made over time to improve the accessibility, acceptability, and availability of testing services. Actors from the community sector played an important role to ensure that public health interventions considered SIH. These findings contribute to the reflections on the lessons learned from COVID-19, highlighting that public health programmes must address structural barriers to accessing healthcare services through multisectoral collaboration. This will be necessary to ensure that future health crises do not further increase SIH.

Seroprevalence of Anti-SARS-CoV-2 Antibodies Among School and Daycare Children: Baseline Results From a Cohort Study in Montreal, Canada (preprint)

Background: Montreal was one of the highest COVID-19 burdened cities in Canada during the first and second waves of the pandemic. We estimated the seroprevalence of SARS-CoV-2 in children and teenagers in four neighbourhoods of Montreal, Canada.Methods: All children attending selected schools and daycares within the four neighbourhoods were invited to participate in the study. Study participation included an online questionnaire that parents completed, followed by at-home dried blood spot (DBS) collection. Serological results were analyzed using a research-based ELISA assay. Statistical analyses included multivariable logistic regression models to calculate average marginal effects and robust standard errors to account for clustering by school or daycare. Several different sociodemographic differences were examined between the seronegative and seropositive children.Findings: There were 30 daycares, 22 primary schools, and 11 secondary schools that participated in the study with 1,632 participants having provided a DBS sample that was of sufficient quality for the serological analysis. The average seroprevalence was 5·8% (95%CI 4·6 to 7·0) but increased over time from 3·2% (95% CI 0·7 to 5·8) in October-November 2020 to 8.4% (95% CI 4·4 to 12·4) in March-April 2021. The children of visible minority parents were nearly twice as likely to be seropositive as children of non-visible minority parents (1·93, 95%CI 1·11 to 2·75). Interpretation: Our results provide a benchmark of the seroprevalence status in Canadian children and provide further evidence of COVID-19 inequities. 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.Funding Information: Public Health Agency of Canada through the COVID-19 Immunity Task Force.Declaration of Interests: All authors declare no competing interests.Ethics Approval Statement: All participants provided informed consent for the survey and ethics approval was received from the research ethics boards of the Université de Montréal and the Centre Hospitalier Universitaire Sainte-Justine.

Social and racial/ethnic differences in parental willingness to vaccinate children against COVID-19 in Montreal, Canada (preprint)

Little is known about the extent of social or racial/ethnic differences in parental hesitancy around COVID-19 vaccination for their children. Using cross-sectional data from an ongoing cohort study in Montreal, Canada, we examined willingness to vaccinate children according to level of education, neighbourhood, and visible minority status. Parents of children aged 2-17 completed a vaccine hesitancy module of an online questionnaire and we used logistic regression to estimate associations between vaccine willingness and education, neighbourhood, and visible minority status. Of the 380 parents who completed the module, 61% were very likely, 25% somewhat likely, 9.2% somewhat unlikely, and 4.5% very unlikely to have their child vaccinated against COVID-19. Visible minority status was strongly associated with willingness to vaccinate, while neighbourhood and level of education were not significantly associated. Further research is needed to quantify these differences on a larger scale and to better understand why certain communities have lower vaccination intention in order to develop tailored strategies to promote vaccine acceptance and uptake.

Learning from the resilience of hospitals and their staff to the COVID-19 pandemic: a scoping review. (preprint)

Background: The COVID-19 pandemic has brought huge strain on hospitals worldwide. It is crucial that we gain a deeper understanding of hospital resilience in this unprecedented moment. This paper aims to report the key strategies and recommendations in terms of hospitals and professionals' resilience to the COVID-19 pandemic, as well as the quality and limitations of research in this field at present. Methods: We conducted a scoping review of evidence on the resilience of hospitals and their staff during the COVID-19 crisis in the first half of 2020. The Stephen B. Thacker CDC Library website was used to identify papers meeting the eligibility criteria, from which we selected 65 publications. After having extracted data, we presented the results synthesis using an "effects-strategies-impacts" resilience framework. Results: We found a wealth of research rapidly produced in the first half of 2020, describing different strategies used to improve hospitals' resilience, particularly in terms of 1) planning, management, and security, and 2) human resources. Research focuses mainly on interventions related to healthcare workers' well-being and mental health, protection protocols, space reorganization, personal protective equipment and resources management, work organization, training, e-health and the use of technologies. Hospital financing, information and communication, and governance were less represented in the literature. Conclusion: The selected literature was dominated by quantitative descriptive case studies, sometimes lacking consideration of methodological limitations. The review revealed a lack of holistic research attempting to unite the topics within a resilience framework. Research on hospitals resilience would benefit from a greater range of analysis to draw more nuanced and contextualized lessons from the multiple specific responses to the crisis. We identified key strategies on how hospitals maintained their resilience when confronted with the COVID-19 pandemic and a range of recommendations for practice.

Seroprevalence of anti-SARS-CoV-2 antibodies among school and daycare children and personnel: Protocol for a cohort study in Montreal, Canada (preprint)

Background: Further evidence is needed to understand the contribution of schools and daycares to the spread of COVID-19 in the context of diverse transmission dynamics and continually evolving public health interventions. The Enfants et COVID-19: Etude de seroprevalence (EnCORE) study will estimate the seroprevalence and seroconversion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among school and daycare children and personnel. In addition, the study will examine associations between seroprevalence and socio-demographic characteristics and reported COVID-19 symptoms and tests, and investigates changes in health, lifestyle and well-being outcomes. Methods: This study includes children and personnel from 62 schools and daycares in four neighbourhoods in Montreal, Canada. All children age 2-17 years attending one of the participating schools or daycares and their parents are invited to participate, as well as a sample of personnel members. Participants respond to brief questionnaires and provide blood samples, collected via dried blood spot (DBS), at baseline (October 2020-March 2021) and follow-up (May-June 2021). Questionnaires include socio-demographic and household characteristics, reported COVID-19 symptoms and tests, potential COVID-19 risk factors and prevention efforts, and health and lifestyle information. Logistic regression using generalized estimating equations will be used to estimate seroprevalence and seroconversion, accounting for school-level clustering. Discussion: The results of the EnCORE study will contribute to our knowledge about SARS-CoV-2 transmission in schools and daycares, which is critical for decisions regarding school attendance and the management of school outbreaks through the remainder of this school year and beyond. Keywords SARS-CoV-2; COVID-19; Children; School; Serology; Protocol; Canada

Lessons learned from the resilience of Chinese hospitals to the COVID-19 pandemic: a scoping review. (preprint)

As the SARS-CoV-2 pandemic has brought huge strain on hospitals worldwide, the resilience shown by Chinas hospitals appears to have been a critical factor in their successful response to the pandemic. This paper aims to determine the key findings, recommendations and lessons learned in terms of hospital resilience during the pandemic, as well as the quality and limitations of research in this field at present. We conducted a scoping review of evidence on the resilience of hospitals in China during the COVID-19 crisis in the first half of 2020. Two online databases (the CNKI and WHO databases) were used to identify papers meeting the eligibility criteria, from which we selected 59 publications (English: n= 26; Chinese: n= 33). After extracting the data, we present an information synthesis using a resilience framework. We found that much research was rapidly produced in the first half of 2020, describing certain strategies used to improve hospital resilience, particularly in three key areas: human resources; management and communication; and security, hygiene and planning. Our search revealed that considerable attention was focused on interventions related to training, healthcare worker well-being, e-health/ telemedicine, and work organization, while other areas, such as hospital financing, information systems and healthcare infrastructure, were less well represented in the literature. We identified a number of lessons learned regarding how Chinas hospitals have maintained resilience when confronted with the SARS-CoV-2 pandemic. However, we also noted that the literature was dominated by descriptive case studies, often lacking consideration of methodological limitations, and that there was a lack of both highly-focused research on individual interventions and holistic research that attempted to unite the topics within a resilience framework. Research on Chinese hospitals would benefit from a greater range of analysis in order to draw more nuanced and contextualised lessons from the responses to the crisis.

A rapid review of equity considerations in large-scale testing campaigns during infectious disease epidemics (preprint)

ContextLarge-scale testing is an intervention that is instrumental for infectious disease control and a central tool for the COVID-19 pandemic. Our rapid review aimed to identify if and how equity has been considered in large-scale testing initiatives. MethodsWe searched Web of Science and PubMed in November 2020 and followed PRISMA recommendations for scoping reviews. Articles were analyzed using descriptive and thematic analysis. ResultsOur search resulted in 291 studies of which 41 were included for data extraction after full article screening. Most of the included articles (83%) reported on HIV-related screening programs, while the remaining programs focused on other sexually transmitted infections (n=3) or COVID-19 (n=4). None of the studies presented a formal definition of (in)equity in testing, however, 23 articles did indirectly include elements of equity in the program or intervention design, largely through the justification of their target population. ConclusionThe studies included in our rapid review did not explicitly consider equity in their design or evaluation. It is imperative that equity is incorporated into the design of infectious disease testing programs and serves as an important reminder of how equity considerations are needed for SARS-CoV-2 testing and vaccination programs.

Learning from Public Health and Hospital Resilience to the SARS-CoV-2 Pandemic: Protocol for a Multiple Case Study (Brazil, Canada, China, France, Japan, and Mali). (preprint)

Background: All prevention efforts currently being implemented for COVID-19 are aimed at reducing the burden on strained health systems and human resources. There has been little research conducted to understand how SARS-CoV-2 has affected healthcare systems and professionals in terms of their work. Finding effective ways to share the knowledge and insight between countries, including lessons learned, is paramount to the international containment and management of the COVID-19 pandemic. The aim of this project is to compare the pandemic response to COVID-19 in Brazil, Canada, China, France, Japan, and Mali. This comparison will be used to identify strengths and weaknesses in the response, including challenges for health professionals and health systems.Methods:  We will use a multiple case study approach with multiple levels of nested analysis. We chose these countries as they represent different continents and different stages of the pandemic. We will focus on several major hospitals and two public health interventions (contact tracing and testing). It is a multidisciplinary research approach that will use qualitative data through observations, document analysis, and interviews, as well as quantitative data based on disease surveillance data and other publicly available data. Given that the methodological approaches of the project are largely qualitative, the ethical risks are minimal. For the quantitative component, the data being used are publicly available.Discussion: We will deliver lessons learned based on a rigorous process and on strong evidence to enable operational-level insight for national and international stakeholders.

Epidemic Curves and COVID-19: How to Reduce The Confusion (preprint)

Introduction: Epidemic curves have played a central role in comparing COVID-19 burden and progression across cities, states, and countries. Methods: We created a series of epidemic curves for Québec and Ontario, comparing and contrasting different COVID-19 outcomes. Results: The different epidemic curves of COVID-19 revealed that crude incidence rates displayed larger differences between the two provinces compared to absolute counts. More notable differences between Ontario and Québec were demonstrated when comparing crude rates of hospitalizations to crude rates of confirmed cases in each province. Crude daily hospitalizations revealed twice the magnitude of hospitalizations for Québec from April to May when compared to Ontario. Conclusions: We recommend using crude rates of hospitalizations, intensive care unit admissions, and mortality for COVID-19 epidemic curve comparison as they reveal important patterns in disease trends, and are more easily comparable between health jurisdictions. A harmonized approach to data presentation is important to not only accurately compare the progression of the pandemic, but also for interpretation of the media and the general public.