Is Perceived Exposure to Mosquitoes Associated with Actual Exposure? Results from Studies in High-Risk and Low-Risk Geographic Areas.

Perceived exposure to mosquitoes plays a fundamental role in the adoption of a range of protective behaviors aiming to prevent and control mosquito-borne disease. However, it is largely unknown in the present literature to what extent perceived exposure is associated with actual exposure. Moreover, the perception of nuisance may depend on the natural environment in which human populations are living, and especially its epidemiological context. In this study, the hypothesis that perceived exposure is driven by mosquito abundance was tested in two different geographic areas. We compared a range of perceived nuisance measures-collected through questionnaires-with egg number measured within ovitraps located in the south of France, which has been recently colonized by an arbovirus vector, and La Martinique island, a tropical French territory, which has a long history of outbreaks of mosquito-borne pathogens. Unexpectedly, only the nuisance due to mosquito noise was correlated with ovitrap activity in southern France. All other perceived exposure measures, both in the south of France and in Martinique, were not correlated with egg number surrounding households investigated. These results suggest the existence of habituation effects that may disturb the engagement in adaptive behaviors in the face of change in the entomological conditions.

An ecological and digital epidemiology analysis on the role of human behavior on the 2014 Chikungunya outbreak in Martinique.

Understanding the spatio-temporal dynamics of endemic infections is of critical importance for a deeper understanding of pathogen transmission, and for the design of more efficient public health strategies. However, very few studies in this domain have focused on emerging infections, generating a gap of knowledge that hampers epidemiological response planning. Here, we analyze the case of a Chikungunya outbreak that occurred in Martinique in 2014. Using time series estimates from a network of sentinel practitioners covering the entire island, we first analyze the spatio-temporal dynamics and show that the largest city has served as the epicenter of this epidemic. We further show that the epidemic spread from there through two different propagation waves moving northwards and southwards, probably by individuals moving along the road network. We then develop a mathematical model to explore the drivers of the temporal dynamics of this mosquito-borne virus. Finally, we show that human behavior, inferred by a textual analysis of messages published on the social network Twitter, is required to explain the epidemiological dynamics over time. Overall, our results suggest that human behavior has been a key component of the outbreak propagation, and we argue that such results can lead to more efficient public health strategies specifically targeting the propagation process.