Modelling interventions during a dengue outbreak

We present a stochastic dynamical model for the transmission of dengue that considers the co-evolution of the spatial dynamics of the vectors (Aedes aegypti) and hosts (human population), allowing the simulation of control strategies adapted to the actual evolution of an epidemic outbreak. We observed that imposing restrictions on the movement of infected humans is not a highly effective strategy. In contrast, isolating infected individuals with high levels of compliance by the human population is efficient even when implemented with delays during an ongoing outbreak. We also studied insecticide-spraying strategies assuming different (hypothetical) efficiencies. We observed that highly efficient fumigation strategies seem to be effective during an outbreak. Nevertheless, taking into account the controversial results on the use of spraying as a single control strategy, we suggest that carrying out combined strategies of fumigation and isolation during an epidemic outbreak should account for a suitable strategy for the attenuation of epidemic outbreaks.Fil: Barmak, Daniel Hernan. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina;Fil: Dorso, Claudio Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina; Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina;Fil: Otero, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina; Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina;Fil: Solari, Hernan Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina; Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina

Modelling dengue epidemic spreading with human mobility

We explored the eect of human mobility on the spatio-temporal dynamics of Dengue with a stochasticmodel that takes into account the epidemiological dynamics of the infected mosquitoes and humans, withdierent mobility patterns of the human population. We observed that human mobility strongly aectsthe spread of infection by increasing the nal size and by changing the morphology of the epidemicoutbreaks. When the spreading of the disease is driven only by mosquito dispersal (ight), a maincentral focus expands diusively. On the contrary, when human mobility is taken into account, multiplefoci appear throughout the evolution of the outbreaks. These secondary foci generated throughout theoutbreaks could be of little importance according to their mass or size compared with the largest mainfocus. However, the coalescence of these foci with the main one generates an eect, through which thelatter develops a size greater than the one obtained in the case driven only by mosquito dispersal. Thisincrease in growth rate due to human mobility and the coalescence of the foci are particularly relevantin temperate cities such as the city of Buenos Aires, since they give more possibilities to the outbreakto grow before the arrival of the low-temperature season. The ndings of this work indicate that humanmobility could be the main driving force in the dynamics of vector epidemics.Keywords: Human mobility, vector-borne diseases, foci coalescence, stochastic modelingFil: Barmak, Daniel Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Dorso, Claudio Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Universidad de Buenos Aires; ArgentinaFil: Otero, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Universidad de Buenos Aires; Argentin

Modeling dengue outbreaks

We introduce a dengue model (SEIR) where the human individuals are treated on an individual basis (IBM) while the mosquito population, produced by an independent model, is treated by compartments (SEI). We study the spread of epidemics by the sole action of the mosquito. Exponential, deterministic and experimental distributions for the (human) exposed period are considered in two weather scenarios, one corresponding to temperate climate and the other to tropical climate. Virus circulation, final epidemic size and duration of outbreaks are considered showing that the results present little sensitivity to the statistics followed by the exposed period provided the median of the distributions are in coincidence. Only the time between an introduced (imported) case and the appearance of the first symptomatic secondary case is sensitive to this distribution. We finally show that the IBM model introduced is precisely a realization of a compartmental model, and that at least in this case, the choice between compartmental models or IBM is only a matter of convenience. (C) 2011 Elsevier Inc. All rights reserved