Marcos Amaku1,2, Dimas Tadeu Covas3, Francisco Antonio Bezerra Coutinho1, Raymundo Soares Azevedo1, Eduardo Massad1,4. 1. Laboratorio de Investigacao Medica (LIM01), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR. 2. Faculdade de Medicina Veterinaria e Zootecnia, Universidade de Sao Paulo, Sao Paulo, SP, BR. 3. Instituto Butantan, Sao Paulo, SP, BR. 4. Escola de Matematica Aplicada, Fundacao Getulio Vargas, Rio de Janeiro, RJ, BR.
Abstract
OBJECTIVES: With the declining numbers of coronavirus disease 2019 (COVID-19) cases in the state of São Paulo, Brazil, social distancing measures have gradually been lifted. However, the risk of a surge in the number of cases cannot be overlooked. Even with the adoption of nonpharmaceutical interventions, such as restrictions on mass gatherings, wearing of masks, and complete or partial closure of schools, other public health measures may help control the epidemic. We aimed to evaluate the impact of the contact tracing of symptomatic individuals on the COVID-19 epidemic regardless of the use of diagnostic testing. METHODS: We developed a mathematical model that includes isolation of symptomatic individuals and tracing of contacts to assess the effects of the contact tracing of symptomatic individuals on the COVID-19 epidemic in the state of São Paulo. RESULTS: For a selection efficacy (proportion of isolated contacts who are infected) of 80%, cases and deaths may be reduced by 80% after 60 days when 5000 symptomatic individuals are isolated per day, each of them together with 10 contacts. On the other hand, for a selection efficacy of 20%, the number of cases and deaths may be reduced by approximately 40% and 50%, respectively, compared with the scenario in which no contact-tracing strategy is implemented. CONCLUSION: Contact tracing of symptomatic individuals may potentially be an alternative strategy when the number of diagnostic tests available is not sufficient for massive testing.
OBJECTIVES: With the declining numbers of coronavirus disease 2019 (COVID-19) cases in the state of São Paulo, Brazil, social distancing measures have gradually been lifted. However, the risk of a surge in the number of cases cannot be overlooked. Even with the adoption of nonpharmaceutical interventions, such as restrictions on mass gatherings, wearing of masks, and complete or partial closure of schools, other public health measures may help control the epidemic. We aimed to evaluate the impact of the contact tracing of symptomatic individuals on the COVID-19 epidemic regardless of the use of diagnostic testing. METHODS: We developed a mathematical model that includes isolation of symptomatic individuals and tracing of contacts to assess the effects of the contact tracing of symptomatic individuals on the COVID-19 epidemic in the state of São Paulo. RESULTS: For a selection efficacy (proportion of isolated contacts who are infected) of 80%, cases and deaths may be reduced by 80% after 60 days when 5000 symptomatic individuals are isolated per day, each of them together with 10 contacts. On the other hand, for a selection efficacy of 20%, the number of cases and deaths may be reduced by approximately 40% and 50%, respectively, compared with the scenario in which no contact-tracing strategy is implemented. CONCLUSION: Contact tracing of symptomatic individuals may potentially be an alternative strategy when the number of diagnostic tests available is not sufficient for massive testing.
Authors: Mirjam E Kretzschmar; Ganna Rozhnova; Martin C J Bootsma; Michiel van Boven; Janneke H H M van de Wijgert; Marc J M Bonten Journal: Lancet Public Health Date: 2020-07-16
Authors: Jaqueline Goes de Jesus; Claudio Sacchi; Darlan da Silva Candido; Ingra Morales Claro; Flávia Cristina Silva Sales; Erika Regina Manuli; Daniela Bernardes Borges da Silva; Terezinha Maria de Paiva; Margarete Aparecida Benega Pinho; Katia Correa de Oliveira Santos; Sarah Catherine Hill; Renato Santana Aguiar; Filipe Romero; Fabiana Cristina Pereira Dos Santos; Claudia Regina Gonçalves; Maria do Carmo Timenetsky; Joshua Quick; Julio Henrique Rosa Croda; Wanderson de Oliveira; Andrew Rambaut; Oliver G. Pybus; Nicholas J. Loman; Ester Cerdeira Sabino; Nuno Rodrigues Faria Journal: Rev Inst Med Trop Sao Paulo Date: 2020-05-11 Impact factor: 1.846
Authors: Eduardo Massad; Marcos Amaku; Annelies Wilder-Smith; Paulo Cesar Costa Dos Santos; Claudio Jose Struchiner; Francisco Antonio Bezerra Coutinho Journal: Epidemiol Infect Date: 2020-06-09 Impact factor: 2.451