Impact evaluation of interventions, addressing spatiotemporal transmission heterogeneity and human mobility, to control arboviruses.

Introduction: In Cuba, dengue has become one of the major mosquito-borne diseases, with a considerable public health impact. Zika and Chikungunya were recently introduced, the former causing a large outbreak. Empirical evidence point out that the most effective mechanism to reduce these infections is to combat the disease-carrying vectors: A. aegypti and A. albopictus. Although these species are being targeted with control methods for many years, the mosquito manages to increase and expand its territory worldwide, related, in part, to social connections, climate change and environmental conditions. It has become evident that there is a need to implement comprehensive disease mitigation strategies, combining different control methods, targeting different stages of the vector development. One of the ways forward to guide control actions, is taking into account the heterogeneity of its transmission. Objectives: To evaluate the population impact of interventions addressing spatiotemporal arbovirus transmission heterogeneity and human mobility, to control arboviruses. Methods: The intervention strategy is two-fold, a preventive one, mainly based on spatial heterogeneity and a reactive one, mainly based on temporal heterogeneity. More specifically, the preventive strategy targets historical transmission hotspots and sites with intense human movement. We hypothesize that a stratified intervention strategy in hotspot areas is effective to reduce the burden of dengue, Zika and chikungunya at a broader geographical scale. The second, reactive, strategy, adds an early warning system to the stratified preventive strategy, and specifically targets to reduce the impact of arbovirus outbreaks. The different steps that will be followed from design to impact evaluation, are: (1) spatiotemporal stratification for the identification of hotspots of arbovirus transmission using a multicomponent approach, (2) an intervention study using a stepped wedge design for the evaluation of complex interventions addressing hotspots of dengue transmission, (3) a modelling approach to forecast the impact of such a municipal stratified intervention strategy, (4) the evaluation of the impact of day-time human movements on effectiveness of the interventions addressed to hotspots, and (5) based on spatial and temporal heterogeneity, designing forecast models to be able to provide an early warning for the appearance of outbreaks. Expected impact/results: Within this PhD project, new insights will be provided on the impact of interventions that are based on spatial and temporal vectorial arbovirus transmission heterogeneity. The results of this project will help to redesign Aedes prevention and control strategies towards a more targeted approach and will deliver critical insights into the dynamics of arbovirus transmission and epidemics, potentially useful for health service organization, identification of sentinel surveillance sites, deployment strategy for a future dengue vaccine and further research on viral epidemiology.

Trefwoorden:B680-volksgezondheid