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A new method to estimate the basic reproductive number of diseases (R 0): An application to the study of dengue epidemics in the Federal District of Brazil Volume 4, issue 2, Mars-Avril 2005

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Authors
Institut de recherche pour le développement, Unité mixte de recherche 182 et Unité de recherche 178, Laboratoire d’océanographie et de dynamique du climat (LOCEAN), Tour 45-55, 4 e étage, 4, place Jussieu, Case 100, 75252 Paris cedex 05, France, Departamento de ciencias de la atmósfera y los océanos, FCEN-UBA, Pabellon II-Piso 2, Buenos Aires, Argentina, Diretoria de vigilância ambiental (DIVAL)/SES-DF, Estrada do Contorno do Bosque, Lote 4, SAIN 70620-000 Brasília, DF, Brésil

Dengue epidemics in Brazil generally begin with a silent phase that lasts for days or weeks, followed by a phase of exponential increase, and then a more or less stable phase before decrease begins. The total number of cases depends on historic, climatic, and ecological factors. Three epidemics in the Federal District (Brazil) were studied to estimate the basic reproductive number R0 and the total number of cases. A new method is proposed, based on the relation between the number of new cases daily and the cumulative number of cases. R 0 is then estimated from the initial slope of the curve describing this relation. Evaluation of the total number of cases requires a more precise method and should take into account some heterogeneity in the rates of contact between people and mosquitoes.