Características epidemiológicas de la infección por SARS-CoV-2 en hogares de escolares de tres instituciones educativas en Asunción y departamento Central entre octubre a noviembre de 2021 / Epidemiological characteristics of SARS-CoV-2 infection in households of schoolchildren from three educational institutions in Asunción and the Central department between October and November 2021

Introducción. Caracterizar la epidemia del SARS-CoV-2 en la comunidad puede aportar datos útiles a las autoridades en la toma de decisiones sobre las instituciones educativas en Paraguay. Objetivo. Describir las características epidemiológicas de la infección por SARS-CoV-2 en los hogares de escolares de tres instituciones de Asunción y departamento Central. Materiales y Métodos. Estudio descriptivo transversal realizado entre el 25 de octubre al 5 de noviembre de 2021. Se aplicaron encuestas estructuradas a los padres o encargados de escolares mediante un cuestionario en formato del formulario de Google enviado a través del WhatsApp desde la Dirección de las instituciones educativas. El cuestionario incluía preguntas sobre el número integrantes del hogar, datos demográficos del encuestado, número de personas con co-morbilidad, personas con COVID-19, con necesidad de hospitalización, número de fallecidos y vacunados contra COVID-19. Resultado. Se obtuvieron datos de 780 hogares, 379 (48,6%) de San Lorenzo, 217 (27,8) de Limpio, 93 (11,9%) de Asunción y 91 de otras localidades de Central (11,7%), el 18,6 % (731/3920) de los integrantes del hogar tuvo COVID-19, de ellos 9,7% (71/731) fue hospitalizado. La mortalidad fue de 0,79% (31/3920) y la letalidad 4,2% (31/731). El 52,7% (2340/3920) ya fue vacunado contra COVID-19 y el 88,2% (2065/2340) de ellos con dosis completa. Conclusión. La prevalencia de COVID-19 estuvo dentro del rango esperado para las infecciones sintomáticas con un alto índice de transmisión intradomiciliaria. Tanto la tasa de mortalidad como letalidad fueron consistentes con los datos nacionales. Palabras Clave: COVID-19; instituciones académicas; Paraguay; características de estudios epidemiológicos

Introduction. Characterizing the SARS-CoV-2 epidemic in the community can provide useful data for the authorities in making decisions on the educational institutions in Paraguay. Objective.To describe the epidemiological characteristics of SARS-CoV-2 infection in the homes of schoolchildren from three institutions in Asunción and the Central Department. Materials and Methods. Cross-sectional descriptive study carried out between October 25 and November 5, 2021. Structured surveys were applied to parents or guardians of schoolchildren through a questionnaire in the format of the Google form sent through WhatsApp from the Directorate of the educational institutions. The questionnaire included questions about the number of household members, demographic data of the respondent, number of people with co-morbidity, people with COVID-19, need of hospitalization, number of death and vaccinated against COVID-19. Results.Data from 780 households were obtained, 379 (48.6%) from San Lorenzo, 217 (27.8) from Limpio, 93 (11.9%) from Asunción and 91 from other localities from Central (11.7%); 18.6% (731/3920) of household members had COVID-19, of them 9.7% (71/731) were hospitalized. Mortality rate was 0.79% (31/3920) and lethality 4.2% (31/731). 52.7% (2,340/3,920) were already vaccinated against COVID-19 and 88.2% (2,065/2,340) of them fully vaccinated. Conclusion.The prevalence of infection was within the expected range for symptomatic COVID-19 infections with a high rate of intradomiciliary transmission. Both the hospitalization and fatality rates were within the range for the country. Key words: COVID-19; schools; Paraguay; epidemiologic study characteristics

Seroprevalencia de infección con SARS-CoV-2 en escolares y docentes en Paraguay / SARS-CoV-2 seroprevalence in school children and teachers in Paraguay

INTRODUCCIÓN: En Paraguay, en el 2021 se produjo el retorno gradual y voluntario a las clases en modalidad semipresencial. OBJETIVO: Estimar la seroprevalencia anti-SARS-CoV2 en los escolares y docentes. MATERIALES Y MÉTODOS: Estudio descriptivo transversal, realizado entre el 25 de octubre y el 5 de noviembre de 2021. Se aplicaron encuestas estructuradas a escolares y docentes de cinco instituciones educativas, dos en Asunción y tres en el Departamento Central; además, se obtuvieron muestras de sangre por punción digital para detección de anticuerpos mediante una prueba rápida inmunocromatográfica. RESULTADOS: Se incluyeron 966 escolares entre 5 a 18 años y 148 docentes, 12,4% (120/966) de los escolares ya había recibido la vacuna anti-COVID-19, que representa 61,9% (120/194) de los estudiantes habilitados para vacunación y 97,3% de los docentes ya antes fue vacunado. El 95,8% de los escolares y 46,6% de los docentes recibieron la vacuna de BNT 162B2 de Pfizer (E.U.A.) y BioNTech (Alemania). El 34,5% de los docentes y 3,9% de los escolares refirieron haber tenido COVID-19. La seroprevalencia sin discriminar estado de vacunación fue 37,7% en escolares y 91,9% en docentes, en los no vacunados fue de 30,9% en escolares y 25,0% en los docentes. En el análisis multivariado solo la vacunación estuvo asociada a la seropositividad. CONCLUSIONES: La alta seroprevalencia anti-SARS-CoV-2 refleja una importante circulación viral en la comunidad. Casi la totalidad del plantel docente tenía el esquema completo de vacunación, y más de la mitad de los estudiantes habilitados había recibido al menos una dosis. Se destaca la alta seropositividad en vacunados. Se recomienda continuar con las medidas preventivas no farmacológicas y vacunación.

BACKGROUND: In Paraguay there has been a gradual and voluntary return to classes in a blended mode. AIM: To estimate the anti-SARS-CoV2 seroprevalence in schoolchildren and teachers. METHODS: Cross-sectional descriptive study, carried out between October 25 and November 5, 2021. Structured surveys were applied to schoolchildren and teachers from five schools, two in Asunción and three in the Central Department. In addition, samples of fingerstick blood for antibody detection by rapid immunochromatographic test were obtained. RESULTS: A total of 148 teachers and 966 schoolchildren were included, 12.4% of the schoolchildren had received the anti-COVID-19 vaccine, which represents 61.9% of the students qualified for vaccination. Among the teachers, 97.3% received the COVID-19 vaccine, 95.9% had the complete schedule, 34.5% of teachers and 3.9% of schoolchildren reported having had COVID-19. The seroprevalence with no vaccine status discrimination was 37.7% in schoolchildren and 91.9% in teachers. In unvaccinated schoolchildren, seroprevalence was 30.9% and in unvaccinated teachers 25.0%. CONCLUSIONS: The high anti-SARS-CoV-2 seroprevalence reflects an important viral circulation in the community. Almost the entire teaching staff had the complete vaccination schedule, and more than half of the qualified students had received at least a dose. The high seropositivity in vaccinated is highlighted. It is recommended to continue with the preventive non-pharmacological measures and vaccination.

Effects of the COVID-19 pandemic in higher education: A data driven analysis for the knowledge acquisition process.

The COVID-19 pandemic abruptly changed the classroom context and presented enormous challenges for all actors in the educational process, who had to overcome multiple difficulties and incorporate new strategies and tools to construct new knowledge. In this work we analyze how student performance was affected, for a particular case of higher education in La Plata, Argentina. We developed an analytical model for the knowledge acquisition process, based on a series of surveys and information on academic performance in both contexts: face-to-face (before the onset of the pandemic) and virtual (during confinement) with 173 students during 2019 and 2020. The information collected allowed us to construct an adequate representation of the process that takes into account the main contributions common to all individuals. We analyzed the significance of the model by means of Artificial Neural Networks and a Multiple Linear Regression Method. We found that the virtual context produced a decrease in motivation to learn. Moreover, the emerging network of contacts built from the interaction between peers reveals different structures in both contexts. In all cases, interaction with teachers turned out to be of the utmost importance in the process of acquiring knowledge. Our results indicate that this process was also strongly influenced by the availability of resources of each student. This reflects the reality of a developing country, which experienced prolonged isolation, giving way to a particular learning context in which we were able to identify key factors that could guide the design of strategies in similar scenarios.

The Knowledge Acquisition Process from a Complex System Perspective: Observations and Models.

We study the knowledge acquisition process in a teaching-learning scenario that takes place within the classroom. We explore two complementary approaches, which include classroom observations and student surveys, and the formulation of theoretical models through the use of statistical physics tools. We develop an analytical model and a set of dynamics agent-based models that allow us to understand global behaviors, as well as to follow individual trajec-tories in the knowledge acquisition process. As a proxy of the final achievements of the students we use their final grade, allowing us to assess the validity of our approach. Our models, supported by observations and surveys, reproduce fairly well the process of acquiring knowledge of the students. This work sheds light on the internal dynamics of the classroom and allows us to understand some global aspects of the teaching-learning process.

Disease and information spreading at different speeds in multiplex networks.

Nowadays, one of the challenges we face when carrying out modeling of epidemic spreading is to develop methods to control disease transmission. In this article we study how the spreading of knowledge of a disease affects the propagation of that disease in a population of interacting individuals. For that, we analyze the interaction between two different processes on multiplex networks: the propagation of an epidemic using the susceptible-infected-susceptible dynamics and the dissemination of information about the disease-and its prevention methods-using the unaware-aware-unaware dynamics, so that informed individuals are less likely to be infected. Unlike previous related models where disease and information spread at the same time scale, we introduce here a parameter that controls the relative speed between the propagation of the two processes. We study the behavior of this model using a mean-field approach that gives results in good agreement with Monte Carlo simulations on homogeneous complex networks. We find that increasing the rate of information dissemination reduces the disease prevalence, as one may expect. However, increasing the speed of the information process as compared to that of the epidemic process has the counterintuitive effect of increasing the disease prevalence. This result opens an interesting discussion about the effects of information spreading on disease propagation.

Epidemic spreading with awareness and different timescales in multiplex networks.

One of the major issues in theoretical modeling of epidemic spreading is the development of methods to control the transmission of an infectious agent. Human behavior plays a fundamental role in the spreading dynamics and can be used to stop a disease from spreading or to reduce its burden, as individuals aware of the presence of a disease can take measures to reduce their exposure to contagion. In this paper, we propose a mathematical model for the spread of diseases with awareness in complex networks. Unlike previous models, the information is propagated following a generalized Maki-Thompson rumor model. Flexibility on the timescale between information and disease spreading is also included. We verify that the velocity characterizing the diffusion of information awareness greatly influences the disease prevalence. We also show that a reduction in the fraction of unaware individuals does not always imply a decrease of the prevalence, as the relative timescale between disease and awareness spreading plays a crucial role in the systems' dynamics. This result is shown to be independent of the network topology. We finally calculate the epidemic threshold of our model, and show that it does not depend on the relative timescale. Our results provide a new view on how information influence disease spreading and can be used for the development of more efficient methods for disease control.

Interacting opinion and disease dynamics in multiplex networks: Discontinuous phase transition and nonmonotonic consensus times.

Opinion formation and disease spreading are among the most studied dynamical processes on complex networks. In real societies, it is expected that these two processes depend on and affect each other. However, little is known about the effects of opinion dynamics over disease dynamics and vice versa, since most studies treat them separately. In this work we study the dynamics of the voter model for opinion formation intertwined with that of the contact process for disease spreading, in a population of agents that interact via two types of connections, social and contact. These two interacting dynamics take place on two layers of networks, coupled through a fraction q of links present in both networks. The probability that an agent updates its state depends on both the opinion and disease states of the interacting partner. We find that the opinion dynamics has striking consequences on the statistical properties of disease spreading. The most important is that the smooth (continuous) transition from a healthy to an endemic phase observed in the contact process, as the infection probability increases beyond a threshold, becomes abrupt (discontinuous) in the two-layer system. Therefore, disregarding the effects of social dynamics on epidemics propagation may lead to a misestimation of the real magnitude of the spreading. Also, an endemic-healthy discontinuous transition is found when the coupling q overcomes a threshold value. Furthermore, we show that the disease dynamics delays the opinion consensus, leading to a consensus time that varies nonmonotonically with q in a large range of the model's parameters. A mean-field approach reveals that the coupled dynamics of opinions and disease can be approximately described by the dynamics of the voter model decoupled from that of the contact process, with effective probabilities of opinion and disease transmission.