Dengue and the risk of urban yellow fever reintroduction in São Paulo State, Brazil

Author(s)

Eduardo Massad ^[1] ; Marcelo Nascimento Burattini ^[2] ; Francisco Antonio Bezerra Coutinho ^[3] ; Luiz Fernandes Lopez ^[4]

Affiliation

^[1] Universidade de São Paulo. Faculdade de Medicina - Brasil

^[2] Universidade de São Paulo. Faculdade de Medicina - Brasil

^[3] Universidade de São Paulo. Faculdade de Medicina - Brasil

^[4] Universidade de São Paulo. Faculdade de Medicina - Brasil

• Document type: Journal article
• Source: Revista de Saúde Pública; v. 37, n. 4, p. 477-484, 2003-08-00.

Abstract

OBJECTIVE: To propose a mathematical method for the estimation of the Basic Reproduction Number, R0, of urban yellow fever in a dengue-infested area. METHODS: The method is based on the assumption that, as the same vector (Aedes aegypti) causes both infections, all the quantities related to the mosquito, estimated from the initial phase of dengue epidemic, could be applied to yellow fever dynamics. It is demonstrated that R0 for yellow fever is, on average, 43% lower than that for dengue. This difference is due to the longer dengue viremia and its shorter extrinsic incubation period. RESULTS: In this study the analysis was expanded to the epidemiological situation of dengue in São Paulo in the year 2001. The total number of dengue cases increased from 3,582 in 2000 to 51,348 in 2001. It was then calculated R0 for yellow fever for every city which have shown R0 of dengue greater than 1. It was also estimated the total number of unprotected people living in highly risky areas for urban yellow fever. CONCLUSIONS: Currently there is a great number of non-vaccinated people living in Aedes aegypti infested area in the state of São Paulo. (AU)

• FAPESP's process: 00/01347-4 - Assessing the impact of individual frailty in vaccine response on the efficacy of BCG
• Grantee: Eduardo Massad
• Support Opportunities: Scholarships abroad - Research