Distribution patterns and feeding success of anchovy, Engraulis anchoita, larvae off southern Brazil

Feeding success and changes in horizontal patchiness relative to size were studied for anchovy, Engraulis anchoita, larvae caught with a Bongo net off southern Brazil. Results show higher feeding success rates during winter, when the combined effect of enrichment, stability and retention mechanisms seems to create optimal conditions for larval feeding. Under optimal feeding conditions larvae of more than 10 mm have higher feeding success rates than smaller size classes. With a simple body structure and low swimming capabilities, larvae of up to 10 mm show a low level of patchiness, low evasion rate of the sampling gear and feeding on small food particles only. Results corroborate the hypothesis of a critical period between two important ontogenic phases: the beginning of exogenous feeding and the onset of active swimming, gas gland buoyancy and school forming behavior.No disponibl

Modeling the impact of school reopening and contact tracing strategies on COVID-19 dynamics in different epidemiologic settings in Brazil

This study was funded by the Brazilian National Council for Scientific and Technological Development (CNPq) - Process # 402834/2020-8 (request for proposals MCTIC/CNPq/FNDCT/MS/SCTIE/Decit Number 07/2020). The funding sources played no role in the study design; collection, analysis, or interpretation of the data; writing the report, or decision to submit the paper for publication. MEB received a technological and industrial scholarship from CNPq (grant number 315854/2020-0). LSF received a masters scholarship from Coordination of Superior Level Staff Improvement (CAPES) (finance code 001). SP was supported by Sao Paulo State Research Support Foundation (FAPESP) (grant number: 2018/24037-4). CF was supported by FAPESP (grant number: 2019/26310-2 and 2017/26770-8). RAK has been supported by CNPq (grant number: 311832/2017-2) and FAPESP (contract number: 2016/01343-7). PIP has been supported by CNPq (grant number: 313055/2020-3). RSK has been supported by CNPq (proc. 312378/2019-0). MQMR received a postdoctoral scholarship from CAPES (grant number 305269/2020-8). CMT has been supported by CNPq productivity fellowship and the National Institute of Science and Technology for Health Technology Assessment (IATS) (proc: 465518/2014-1). AMB received a technological and industrial scholarship from CNPq (grant number 402834/2020-8). LMS received a technological and industrial scholarship from CNPq (grant number 315866/2020-9). JAFD-F has been supported by CNPq productivity fellowship and the National Institutes for Science and Technology in Ecology, Evolution and Biodiversity Conservation (INCT-EEC), supported by MCTIC/CNPq (proc. 465610/2014-5) and FAPEG (proc. 201810267000023).Preprin

Modelling the impact of school reopening and contact tracing strategies on Covid-19 dynamics in different epidemiologic settings in Brazil

We simulate the impact of school reopening during the COVID-19 pandemic in three major urban centers in Brazil to identify the epidemiological indicators and the best timing for the return of in-school activities and the effect of contact tracing as a mitigation measure. Our goal is to offer guidelines for evidence-based policymaking. We implement an extended SEIR model stratified by age and considering contact networks in different settings – school, home, work, and community, in which the infection transmission rate is affected by various intervention measures. After fitting epidemiological and demographic data, we simulate scenarios with increasing school transmission due to school reopening, and also estimate the number of hospitalization and deaths averted by the implementation of contact tracing. Reopening schools results in a non-linear increase in reported COVID-19 cases and deaths, which is highly dependent on infection and disease incidence at the time of reopening. When contact tracing and quarantining are restricted to school and home settings, a large number of daily tests is required to produce significant effects in reducing the total number of hospitalizations and deaths. Policymakers should carefully consider the epidemiological context and timing regarding the implementation of school closure and return of in-person school activities. While contact tracing strategies prevent new infections within school en- vironments, they alone are not sufficient to avoid significant impacts on community transmission

Modeling the impact of child vaccination (5–11 y) on overall COVID-19 related hospitalizations and mortality in a context of omicron variant predominance and different vaccination coverage paces in Brazil

Background Developing countries have experienced significant COVID-19 disease burden. With the emergence of new variants, particularly omicron, the disease burden in children has increased. When the first COVID-19 vaccine was approved for use in children aged 5–11 years of age, very few countries recommended vaccination due to limited risk-benefit evidence for vaccination of this population. In Brazil, ranking second in the global COVID-19 death toll, the childhood COVID-19 disease burden increased significantly in early 2022. This prompted a risk-benefit assessment of the introduction and scaling-up of COVID-19 vaccination of children. Methods To estimate the potential impact of vaccinating children aged 5–11 years with mRNA-based COVID-19 vaccine in the context of omicron dominance, we developed a discrete-time SEIR-like model stratified in age groups, considering a three-month time horizon. We considered three scenarios: No vaccination, slow, and maximum vaccination paces. In each scenario, we estimated the potential reduction in total COVID-19 cases, hospitalizations, deaths, hospitalization costs, and potential years of life lost, considering the absence of vaccination as the base-case scenario. Findings We estimated that vaccinating at a maximum pace could prevent, between mid-January and April 2022, about 26,000 COVID-19 hospitalizations, and 4200 deaths in all age groups; of which 5400 hospitalizations and 410 deaths in children aged 5–11 years. Continuing vaccination at a slow/current pace would prevent 1450 deaths and 9700 COVID-19 hospitalizations in all age groups in this same time period; of which 180 deaths and 2390 hospitalizations in children only. Interpretation Maximum vaccination of children results in a significant reduction of COVID-19 hospitalizations and deaths and should be enforced in developing countries with significant disease incidence in children

Prevalence of bronchial asthma and related symptoms in schoolchildren in the Federal District of Brazil: correlations with socioeconomic levels

Objetivo: Avaliar a prevalência de asma e sintomas a ela relacionados no Distrito Federal e sua relação com o nível socioeconômico, utilizando o questionário escrito do International Study of Asthma and Allergies in Childhood. Métodos: Foram avaliadas 6.437 crianças, em escolas públicas e particulares, divididas em: 3.183 crianças de seis a sete anos e 3.254 de treze a catorze anos. Os dados foram analisados por sexo e grupo socioeconômico (teste do qui-quadrado). Resultados: A prevalência encontrada de asma brônquica no Distrito Federal foi de 12,1% e 13,8% nas faixas etárias de seis a sete anos e treze a catorze anos, respectivamente (p < 0,04). Na faixa etária de seis a sete anos, o sexo masculino apresentou prevalências significativamente maiores de asma diagnosticada e de sintomas (p < 0,001), enquanto que na de treze a catorze anos, a maior prevalência de sintomas ocorreu no sexo feminino (p < 0,05). O grupo de piores condições socioeconômicas apresentou maiores taxas de sintomas relacionados à asma nas duas faixas etárias (p < 0,05). O diagnóstico de asma foi mais freqüente na classe social menos favorecida (p < 0,001) para o questionário respondido pelos pais. Entre os adolescentes, houve maior número de diagnósticos de asma no grupo de nível socioeconômico mais elevado (p = 0,001). Conclusão: O grupo economicamente desfavorecido apresentou prevalências maiores de sintomas de asma, assim como crises de maior gravidade. Também a prevalência de asma provável foi maior neste grupo que a de asma diagnosticada, o que sugere seu subdiagnóstico.Objective: To evaluate the asthma prevalence in the Federal District of Brazil, using the questionnaire developed for the International Study of Asthma and Allergies in Childhood to look for correlations with socioeconomic levels. Methods: A total of 6437 children (3183 from six to seven years old and 3254 from thirteen to fourteen years old), attending public or private schools, were evaluated. The data were analyzed by gender and socioeconomic status (chi-square test). Results: The prevalence of asthma in the Federal District was 12.1% among the six- and seven-year-olds and 13.8% among the thirteen- and fourteen-year-olds (p < 0.04). In the six-to-seven age bracket, asthma prevalence was significantly greater, and asthma-related symptoms were more frequent, among males (p < 0.001). In contrast, asthma-related symptoms were more frequent among females in the thirteen-to-fourteen age bracket (p < 0.05). Children belonging to the lowest socioeconomic class, as determined by the responses given on the questionnaire completed by the parents, presented the highest prevalence of asthma, regardless of age bracket (p < 0.001). Among such children, asthma-related symptoms were also more frequent (p < 0.05). In the thirteen-to-fourteen age bracket, the prevalence of asthma was greater among those belonging to the highest socioeconomic class (p = 0.001). Conclusions: Overall, economically disadvantaged children more frequently presented asthma-related symptoms and experienced asthma attacks that were of greater severity. In addition, the prevalence of suspected asthma was higher than that of diagnosed asthma in this group, suggesting that asthma is underdiagnosed in children belonging to the lowest socioeconomic class

Distribution patterns and feeding success of anchovy, Engraulis anchoita, larvae off southern Brazil

Feeding success and changes in horizontal patchiness relative to size were studied for anchovy, Engraulis anchoita, larvae caught with a Bongo net off southern Brazil. Results show higher feeding success rates during winter, when the combined effect of enrichment, stability and retention mechanisms seems to create optimal conditions for larval feed-ing. Under optimal feeding conditions larvae of more than 10 mm have higher feeding success rates than smaller size class- es. With a simple body structure and low swimming capabilities, larvae of up to 10 mm show a low level of patchiness, low evasion rate of the sampling gear and feeding on small food particles only. Results corroborate the hypothesis of a critical period between two important ontogenic phases: the beginning of exogenous feeding and the onset of active swimming, gas gland buoyancy and school forming behavior

Prevalência de asma brônquica e de sintomas a ela relacionados em escolares do Distrito Federal e sua relação com o nível socioeconômico Prevalence of bronchial asthma and related symptoms in schoolchildren in the Federal District of Brazil: correlations with socioeconomic levels

OBJETIVO: Avaliar a prevalência de asma e sintomas a ela relacionados no Distrito Federal e sua relação com o nível socioeconômico, utilizando o questionário escrito do International Study of Asthma and Allergies in Childhood. MÉTODOS: Foram avaliadas 6.437 crianças, em escolas públicas e particulares, divididas em: 3.183 crianças de seis a sete anos e 3.254 de treze a catorze anos. Os dados foram analisados por sexo e grupo socioeconômico (teste do qui-quadrado). RESULTADOS: A prevalência encontrada de asma brônquica no Distrito Federal foi de 12,1% e 13,8% nas faixas etárias de seis a sete anos e treze a catorze anos, respectivamente (p < 0,04). Na faixa etária de seis a sete anos, o sexo masculino apresentou prevalências significativamente maiores de asma diagnosticada e de sintomas (p < 0,001), enquanto que na de treze a catorze anos, a maior prevalência de sintomas ocorreu no sexo feminino (p < 0,05). O grupo de piores condições socioeconômicas apresentou maiores taxas de sintomas relacionados à asma nas duas faixas etárias (p < 0,05). O diagnóstico de asma foi mais freqüente na classe social menos favorecida (p < 0,001) para o questionário respondido pelos pais. Entre os adolescentes, houve maior número de diagnósticos de asma no grupo de nível socioeconômico mais elevado (p = 0,001). CONCLUSÃO: O grupo economicamente desfavorecido apresentou prevalências maiores de sintomas de asma, assim como crises de maior gravidade. Também a prevalência de asma provável foi maior neste grupo que a de asma diagnosticada, o que sugere seu subdiagnóstico.<br>OBJECTIVE: To evaluate the asthma prevalence in the Federal District of Brazil, using the questionnaire developed for the International Study of Asthma and Allergies in Childhood to look for correlations with socioeconomic levels. METHODS: A total of 6437 children (3183 from six to seven years old and 3254 from thirteen to fourteen years old), attending public or private schools, were evaluated. The data were analyzed by gender and socioeconomic status (chi-square test). RESULTS: The prevalence of asthma in the Federal District was 12.1% among the six- and seven-year-olds and 13.8% among the thirteen- and fourteen-year-olds (p < 0.04). In the six-to-seven age bracket, asthma prevalence was significantly greater, and asthma-related symptoms were more frequent, among males (p < 0.001). In contrast, asthma-related symptoms were more frequent among females in the thirteen-to-fourteen age bracket (p < 0.05). Children belonging to the lowest socioeconomic class, as determined by the responses given on the questionnaire completed by the parents, presented the highest prevalence of asthma, regardless of age bracket (p < 0.001). Among such children, asthma-related symptoms were also more frequent (p < 0.05). In the thirteen-to-fourteen age bracket, the prevalence of asthma was greater among those belonging to the highest socioeconomic class (p = 0.001). CONCLUSIONS: Overall, economically disadvantaged children more frequently presented asthma-related symptoms and experienced asthma attacks that were of greater severity. In addition, the prevalence of suspected asthma was higher than that of diagnosed asthma in this group, suggesting that asthma is underdiagnosed in children belonging to the lowest socioeconomic class

Modeling the impact of child vaccination (5–11 y) on overall COVID-19 related hospitalizations and mortality in a context of omicron variant predominance and different vaccination coverage paces in BrazilResearch in context

Summary: Background: Developing countries have experienced significant COVID-19 disease burden. With the emergence of new variants, particularly omicron, the disease burden in children has increased. When the first COVID-19 vaccine was approved for use in children aged 5–11 years of age, very few countries recommended vaccination due to limited risk-benefit evidence for vaccination of this population. In Brazil, ranking second in the global COVID-19 death toll, the childhood COVID-19 disease burden increased significantly in early 2022. This prompted a risk-benefit assessment of the introduction and scaling-up of COVID-19 vaccination of children. Methods: To estimate the potential impact of vaccinating children aged 5–11 years with mRNA-based COVID-19 vaccine in the context of omicron dominance, we developed a discrete-time SEIR-like model stratified in age groups, considering a three-month time horizon. We considered three scenarios: No vaccination, slow, and maximum vaccination paces. In each scenario, we estimated the potential reduction in total COVID-19 cases, hospitalizations, deaths, hospitalization costs, and potential years of life lost, considering the absence of vaccination as the base-case scenario. Findings: We estimated that vaccinating at a maximum pace could prevent, between mid-January and April 2022, about 26,000 COVID-19 hospitalizations, and 4200 deaths in all age groups; of which 5400 hospitalizations and 410 deaths in children aged 5–11 years. Continuing vaccination at a slow/current pace would prevent 1450 deaths and 9700 COVID-19 hospitalizations in all age groups in this same time period; of which 180 deaths and 2390 hospitalizations in children only. Interpretation: Maximum vaccination of children results in a significant reduction of COVID-19 hospitalizations and deaths and should be enforced in developing countries with significant disease incidence in children. Funding: This manuscript was funded by the Brazilian Council for Scientific and Technology Development (CNPq – Process # 402834/2020-8)