Logo do repositório

DEP - Artigos em revistas internacionais

URI permanente para esta coleção:

http://hdl.handle.net/10400.18/29

Navegar

Percorrer DEP - Artigos em revistas internacionais por Domínios Científicos e Tecnológicos (FOS) "Ciências Naturais::Ciências Biológicas"

A mostrar 1 - 2 de 2
  • Assessing the role of children in the COVID-19 pandemic in Belgium using perturbation analysis
    Publication . Angeli, Leonardo; Caetano, Constantino Pereira; Franco, Nicolas; Coletti, Pietro; Faes, Christel; Molenberghs, Geert; Beutels, Philippe; Abrams, Steven; Willem, Lander; Hens, Niel
    Understanding the evolving role of different age groups in virus transmission is essential for effective pandemic management. We investigated SARS-CoV-2 transmission in Belgium from November 2020 to February 2022, focusing on age-specific patterns. Using a next generation matrix approach integrating social contact data and simulating population susceptibility evolution, we performed a longitudinal perturbation analysis of the effective reproduction number to unravel age-specific transmission dynamics. From November to December 2020, adults in the [18, 60) age group were the main transmission drivers, while children contributed marginally. This pattern shifted between January and March 2021, when in-person education resumed, and the Alpha variant emerged: children aged under 12 years old were crucial in transmission. Stringent social distancing measures in March 2021 helped diminish the noticeable contribution of the [18, 30) age group. By June 2021, as the Delta variant became the predominant strain, adults aged [18, 40) years emerged as main contributors to transmission, with a resurgence in children’s contribution during September-October 2021. This study highlights the effectiveness of our methodology in identifying age-specific transmission patterns.
    2025-03-05Artigo científico Acesso aberto Ver mais
  • Impact of non-pharmacological interventions on the first wave of COVID-19 in Portugal 2020
    Publication . Loyens, Dinis B.; Caetano, Constantino; Matias-Dias, Carlos
    Introduction: The COVID-19 pandemic caused over 7 million global deaths. Without vaccines during the first wave, governments implemented nonpharmacological interventions (NPIs) such as lockdowns, school closures, and travel restrictions. This study quantifies the impact of NPIs on COVID-19 transmission in Portugal between 24th February and 1st May. Methods: A compartmental SEIR (Susceptible, Exposed, Infectious, Removed) model was employed to simulate the first COVID-19 wave in Portugal, using a Bayesian approach and symptom-onset incidence data. The effect of the lockdown, which began on March 22, 2020, on the effective reproductive number, R t was measured. A counterfactual scenario was created to ascertain the number of cases prevented by the NPIs during the first 15 days after the implementation of NPI. Results: The lockdown reduced overall transmission by 68·6 % (95%Credible Interval (95%CrI): 59·2 %; 77·5 %), almost immediately. This corresponds to a reduction in the effective reproductive number from 2·56 (95%CrI: 2·08; 3·40) to 0·80 (95%CrI: 0·76; 0·84). The counterfactual scenario estimated that the lockdown prevented 118052 (95%CrI: 99464; 145605) cases between 24th February and 6th April. Discussion: The lockdown significantly reduced COVID-19 transmission in Portugal, bringing Rt below 1, meaning each person infected fewer than one individual. While costly, lockdowns effectively control disease spread in the absence of vaccines. Conclusion: Our findings suggest NPIs curbed epidemic transmission, reducing Rt below 1 and easing hospital loads and deaths. This research will help inform future pandemic decision-making and infectious disease modeling worldwide.
    2025-01-31Artigo científico Acesso aberto Ver mais