Seminário de Biomatemática

18 de Dezembro 2008, 16h00

Epidemiological and economic analyses of dengue surveillance and control
Complexo Interdisciplinar, Sala B3-01

Paula Luz (Fio Cruz, Rio, and Yale, New Hell)

Abstract:

In this work, we used several quantitative methods to improve the understanding of dengue dynamics within populations and to evaluate the impact of control interventions. First, we constructed an autoregressive integrated moving average (ARIMA) model for monitoring and predicting dengue incidence in Rio de Janeiro, Brazil. In addition, we evaluated the role of climate variables in improving the predictive power of the model. We reached a model that describes and predicts dengue incidence and found that climate variables offer minor improvements to the predictive power.
Second, we constructed a seasonal population dynamics model of the dengue mosquito vector, Aedes aegypti, for the analysis of insecticide-based vector control interventions, the current strategy for curtailing dengue transmission. We assessed the impact of interventions on reducing mosquito abundance and predicted evolutionary trajectories of insecticide resistance. We demonstrated that combined targeting of larvae and adults during the dengue season is optimal­an intervention that contrasts with year-long continuous larval control adopted in several settings where dengue transmission occurs.
Third, we used the non-monetary index disability adjusted life years (DALYs) to estimate the morbidity and mortality imposed by dengue in Rio de Janeiro and Brazil. We revealed that the dengue burden is significant in the city and state of Rio de Janeiro, as well as in Brazil overall. Our results showed that to fully estimate the dengue burden, it is necessary to account for all clinical syndromes over a period of multiple years. Fourth, we integrated a dengue transmission model with a dengue burden analysis to comparatively evaluate the effectiveness of vector-control intervention strategies. We calculated the health burden in terms of DALYs lost, as well as the direct and indirect medical costs incurred by dengue cases. We found that both larval and adult control can save DALYs. However, the optimal intervention strategy varied depending on the time horizon of analysis. We revealed that the medical costs saved from averted illness make specific vector control interventions cost-effective strategies for the policy maker in charge of dengue budget allocation.
Finally, the strategies of two or three high-efficacy larval control applications annually were found to be highly-cost effective and cost-effective, respectively.
In summary, our contributions included improved surveillance, comprehensive health burden evaluation and optimized vector control.

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