Early determination of the reproductive number for vector-borne diseases: the case of dengue in Brazil.

Objective: To evaluate a new method of deriving the reproductive number for vector-borne diseases from the early epidemic curves for vector-borne diseases with incubations in the vectors and in the hosts.
Method: We applied the model to several dengue epidemics in different climatic regions of Brazil: Brasilia, Belém, Fortaleza, Boa Vista.
Results: The new method leads to higher estimates of the reproductive number than previous models.
Conclusion: At present, Aedes aegypti densities, the meeting of more compatible strains of viruses and mosquitoes, may lead to re-emergence of urban yellow fever epidemics.