Impact of non-pharmacological interventions on the first wave of COVID-19 in Portugal 2020
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 transmiss...
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| Format: | Article |
| Language: | English |
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Elsevier
2025-02-01
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| Series: | Heliyon |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2405844024176001 |
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| author | Dinis B. Loyens Constantino Caetano Carlos Matias-Dias |
| author_facet | Dinis B. Loyens Constantino Caetano Carlos Matias-Dias |
| author_sort | Dinis B. Loyens |
| collection | DOAJ |
| description | 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, Rt 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. |
| format | Article |
| id | doaj-art-b3b4c8e3d06746509594598470f69f16 |
| institution | Kabale University |
| issn | 2405-8440 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Heliyon |
| spelling | doaj-art-b3b4c8e3d06746509594598470f69f162025-02-12T05:31:21ZengElsevierHeliyon2405-84402025-02-01114e41569Impact of non-pharmacological interventions on the first wave of COVID-19 in Portugal 2020Dinis B. Loyens0Constantino Caetano1Carlos Matias-Dias2Unidade de Saúde Pública da Amadora, Unidade Local de Saúde Amadora/Sintra, Portugal; Departamento de Epidemiologia, Instituto Nacional de Saúde Doutor Ricardo Jorge, PortugalDepartamento de Epidemiologia, Instituto Nacional de Saúde Doutor Ricardo Jorge, PortugalDepartamento de Epidemiologia, Instituto Nacional de Saúde Doutor Ricardo Jorge, PortugalIntroduction: 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, Rt 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.http://www.sciencedirect.com/science/article/pii/S2405844024176001 |
| spellingShingle | Dinis B. Loyens Constantino Caetano Carlos Matias-Dias Impact of non-pharmacological interventions on the first wave of COVID-19 in Portugal 2020 Heliyon |
| title | Impact of non-pharmacological interventions on the first wave of COVID-19 in Portugal 2020 |
| title_full | Impact of non-pharmacological interventions on the first wave of COVID-19 in Portugal 2020 |
| title_fullStr | Impact of non-pharmacological interventions on the first wave of COVID-19 in Portugal 2020 |
| title_full_unstemmed | Impact of non-pharmacological interventions on the first wave of COVID-19 in Portugal 2020 |
| title_short | Impact of non-pharmacological interventions on the first wave of COVID-19 in Portugal 2020 |
| title_sort | impact of non pharmacological interventions on the first wave of covid 19 in portugal 2020 |
| url | http://www.sciencedirect.com/science/article/pii/S2405844024176001 |
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