Lockdown as an Intervention Measure to Mitigate the Spread of COVID-19: a modeling study.

INTRODUCTION: This work aims to develop a biomathematical transmission model of COVID-19, in the State of Sergipe, Brazil, to estimate the distribution of cases over time and project the impact on the spread of the epidemic outbreak due to interventions and control measures over the local population. METHODS: This is an epidemiological mathematical modeling study conducted to analyze the dynamics of the accumulated cases of COVID-19, which used a logistic growth model that adds a term of withdrawal of individuals as a control measure. Three possible COVID-19 propagation scenarios were simulated based on three different rates of withdrawal of individuals. They were adjusted with real data of the infected and measures of control over the population. RESULTS: The lockdown would be the best scenario, with a lower incidence of infected people, when compared to the other measures. The number of infected people would grow slowly over the months, and the number of symptomatic individuals in this scenario would be 40,265 cases. We noticed that the State of Sergipe is still in the initial stage of the disease in the scenarios. It was possible to observe that the peak of cases and the equilibrium, in the current situation of social isolation, will occur when reaching the new support capacity, at the end of August in approximately 1,171,353 infected individuals. CONCLUSIONS: We established that lockdown is the intervention with the highest ability to mitigate the spread of the virus among the population.

Lockdown as an intervention measure to mitigate the spread of COVID-19: a modeling study / Lockdown como medida de intervenção para mitigar a propagação da COVID-19: um estudo de modelagem

Introduction: This work aims to develop a biomathematical model of transmission of COVID-19, in the State of Sergipe, Brazil, to estimate the distribution of cases over time and to project the impact on the spread of the epidemic outbreak due to interventions and control measures on the local population. Methods: Epidemiological mathematical modeling study, carried out to analyze the dynamics of accumulated cases of COVID-19, which used a logistic growth model that adds a term of withdrawal of individuals as a control measure. Three possible scenarios of COVID-19 propagation based on three different withdrawal rates of individuals were simulated. Each of the rates is adjusted with actual data on the number of infected and control measures on the population. Results: The extreme measure of total isolation, or lockdown, would be the best scenario, presenting a lower incidence of infected, when compared to the other measures. The number of infected would grow slowly over the months and the number of symptomatic individuals in this scenario would be 40,265 cases. It was noticed that the State of Sergipe is still in the initial phase of the disease, in any of the scenarios. It was possible to observe that the peak of cases and balance, in the current scenario of social isolation, will take place when the new support capacity is reached, at the end of August in approximately 1,171,353 infected individuals. Conclusion: It was noticed that lockdown is the intervention with greater capacity to mitigate the spread of the virus by the population. Keywords: COVID-19, Coronavirus Infection, Social Isolation, Epidemiology.

Objetivo: Desarrollar un modelo biomatemático de transmisión de la enfermedad COVID-19, en el estado Sergipe, Brasil, a fin de estimar la distribución de los casos a lo largo del tiempo y proyectar el impacto de las intervenciones y medidas de control sobre la población local sobre la propagación del brote epidémico. Métodos: Estudio de modelaje matemático epidemiológico, realizado para analizar la dinámica de los casos acumulados de COVID-19, utilizando un modelo de crecimiento logístico que agrega un término de retirada de individuos como medida de control. Fueron simulados tres posibles escenarios de propagación de COVID-19 basados en tres diferentes tasas de retirada de individuos. Cada una de las tasas fue ajustada con datos reales sobre el número de infectados y las medidas de control sobre la población.  Resultados: La medida extrema de aislamiento total, el lockdown, sería el mejor escenario, presentando menor incidencia de infectados, comparando con las demás medidas. El número de infectados crecería lentamente a lo largo de los meses y el número de individuos sintomáticos en ese escenario sería de 40.265 casos. En todos los escenarios estudiados, se percibió que el estado Sergipe aún se encuentra en la fase inicial de la enfermedad.  Fue posible observar que el pico de los casos y el equilibrio, en el escenario actual de aislamiento social, se darán al alcanzar la nueva capacidad soporte, al final de agosto con aproximadamente 1.171.353 individuos infectados. Conclusión: Se percibió que el lockdown es la intervención con mayor capacidad de mitigar la propagación del virus en la población.

Introdução: Este trabalho visa desenvolver um modelo biomatemático de transmissão da COVID-19, no estado de Sergipe, Brasil, a fim de estimar a distribuição dos casos ao longo do tempo e projetar o impacto na propagação do surto epidêmico devido às intervenções e medidas de controle sobre a população local. Métodos: Estudo de modelagem matemática epidemiológica, realizado para analisar a dinâmica dos casos acumulados de COVID-19, que utilizou um modelo de crescimento logístico que adiciona um termo de retirada de indivíduos como medida de controle. Foram simulados três possíveis cenários de propagação da COVID-19 baseados em três diferentes taxas de retirada de indivíduos. Cada uma das taxas é ajustada com dados reais sobre número de infetados e as medidas de controle sobre a população.  Resultados: A medida extrema de isolamento total, ou lockdown, seria o melhor cenário, apresentando menor incidência de infectados, quando comparado às demais medidas. O número de infectados cresceria vagarosamente ao longo dos meses e o número de indivíduos sintomáticos nesse cenário seria de 40.265 casos. Percebeu-se que o Estado de Sergipe ainda encontra-se na fase inicial da doença, em quaisquer dos cenários. Foi possível observar que o pico dos casos e o equilíbrio, no cenário atual de isolamento social, se darão quando atingir a nova capacidade suporte, ao final de agosto em aproximadamente 1.171.353 indivíduos infectados. Conclusão: Percebeu-se que o lockdown é a intervenção com maior capacidade de mitigação da propagação do vírus pela população.

Lockdown as an Intervention Measure to Mitigate the Spread of COVID-19: a modeling study

Abstract INTRODUCTION: This work aims to develop a biomathematical transmission model of COVID-19, in the State of Sergipe, Brazil, to estimate the distribution of cases over time and project the impact on the spread of the epidemic outbreak due to interventions and control measures over the local population. METHODS: This is an epidemiological mathematical modeling study conducted to analyze the dynamics of the accumulated cases of COVID-19, which used a logistic growth model that adds a term of withdrawal of individuals as a control measure. Three possible COVID-19 propagation scenarios were simulated based on three different rates of withdrawal of individuals. They were adjusted with real data of the infected and measures of control over the population. RESULTS: The lockdown would be the best scenario, with a lower incidence of infected people, when compared to the other measures. The number of infected people would grow slowly over the months, and the number of symptomatic individuals in this scenario would be 40,265 cases. We noticed that the State of Sergipe is still in the initial stage of the disease in the scenarios. It was possible to observe that the peak of cases and the equilibrium, in the current situation of social isolation, will occur when reaching the new support capacity, at the end of August in approximately 1,171,353 infected individuals. CONCLUSIONS: We established that lockdown is the intervention with the highest ability to mitigate the spread of the virus among the population.