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

ImportanceRepeated 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. ObjectiveTo use serological testing to assess the prevalence, seroconversion, and seroreversion of infection-induced SARS-CoV-2 antibodies in children and adolescents in Montreal, Canada. DesignThis 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. SettingPopulation-based sample. ParticipantsChildren and adolescents aged 2 to 17 years in Montreal, Canada. ExposurePotential exposure to SARS-CoV-2. Main Outcomes and MeasuresParticipants 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. ResultsThe 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{middle dot}8% (95% CI 4{middle dot}8-7{middle dot}1), which increased to 10{middle dot}5% and 10{middle dot}9% for the respective follow-ups (95% CI 8{middle dot}6-12{middle dot}7; 95% CI 8{middle dot}8-13{middle dot}5). The overall average crude rate of seroconversion over the study period was 12{middle dot}7 per 100 person-years (95% CI 10{middle dot}9-14{middle dot}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 RelevanceThe 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. KEY POINTSO_ST_ABSQuestionC_ST_ABSWhat was the rate of seroconversion and time to seroreversion for SARS-CoV-2 antibodies among children and adolescents in Montreal between October 2020 to January 2022? FindingsThe overall average crude rate of seroconversion was 12{middle dot}7 per 100 person-years (95% CI 10{middle dot}9-14{middle dot}5). We observed higher rates of seroconversion in children who were female, whose parent identified as a racial or ethnic minority, and in households with incomes less than 100K. Among all children who seroconverted, 71% had not been previously diagnosed with COVID-19. Median time to seroreversion was 7{middle dot}5 months. MeaningEven before the emergence of the Omicron variants, we observed a high rate of seroconversion for infection-induced SARS-CoV-2 antibodies along with widespread antibody waning by one year. Many children and adolescents seroconverted despite not receiving a prior COVID-19 diagnosis, indicating that RT-PCR and antigen testing continue to underestimate true disease prevalence.

How the Malian press treated hydroxychloroquine at the beginning of the COVID-19 pandemic

BackgroundThe global debate on the efficacy of hydroxychloroquine (HCQ) on COVID-19 has gone far beyond the scientific framework and has been highly politicized. These issues immediately invested the debate on HCQ and made it an object of particular crystallization. This study analyzes, through the Malian press, the echo of this debate in the national background. MethodsMixed methods design, based on a review of 452 articles about COVID-19 published by six major Malian newspapers, from January 1st to July 31st 2020. Results of a content analysis with WORDSTAT8 software were further explained by a thematic qualitative analysis using and deductive-indictive approach. ResultsThe debate on HCQ has had very little echo in the Malian press despite some interest, because of a lack of anchoring and thus of a "response" at the national level. The national health authorities, who adopted the treatment as part of clinical trials, and the press, stayed away from both the medical and the "ideological" components of the debate, despite these a priori directly involved a country like Mali. ConclusionsThe paper sheds light on the issues at stake in the HCQ debate based on a case study of an atypical country in terms of impacts of Covid-19. The governance of COVID helped crystallize political opposition to the presidential regime leading to a coup in August.

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

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.

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

BackgroundThe success of current and prospective COVID-19 vaccine campaigns for children and adolescents will in part depend on the willingness of parents to accept vaccination. This study examined social determinants of parental COVID-19 vaccine acceptance and uptake for children and adolescents. MethodsWe used cross-sectional data from an ongoing COVID-19 cohort study in Montreal, Canada and included all parents of 2 to 18-year-olds who completed an online questionnaire between May 18 and June 26, 2021 (n=809). We calculated child age-adjusted prevalence estimates of vaccine acceptance by parental education, race/ethnicity, birthplace, household income, and neighbourhood, and used multinomial logistic regression to estimate adjusted prevalence differences (aPD) and ratios (aPR). Social determinants of vaccine uptake were estimated for the vaccine-eligible sample of 12 to 18 year-olds (n=306). ResultsIntention to vaccinate children against COVID-19 was high, with only 12.4% of parents unlikely to have their child vaccinated. Parents with younger children were less likely to accept vaccination, as were those from lower-income households, racialized groups, and those born outside Canada. The percent of parents whose child was vaccinated or very likely to be vaccinated was 18.4 percentage points lower among those with annual household incomes <$100,000 vs. [≥]$150,000 (95% CI: 10.1 to 26.7). Racialized parents reported greater unwillingness to vaccinate compared to White parents (aPD=10.3; 95% CI: 1.5, 19.1). Vaccine-eligible adolescents from the most deprived neighbourhood were half as likely to be vaccinated compared to those from the least deprived neighbourhood (aPR = 0.48; 95% CI: 0.18 to 0.77). InterpretationThis study identified marked social inequalities in COVID-19 vaccine acceptance and uptake for children and adolescents. Efforts are needed to reach disadvantaged and marginalized populations with tailored strategies that promote informed decision making and facilitate access to vaccination.

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

BackgroundThe 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. MethodsWe 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. ResultsWe 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. ConclusionThe 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

BackgroundFurther 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. MethodsThis 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. DiscussionThe 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.

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

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

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.