Climate change and the rising infectiousness of dengue

Abstract

The disease burden of dengue has been steadily rising over the last half-century due to a multitude of factors, including global trade and travel, urbanization, population growth, and climate variability and change, that facilitate conductive conditions for the proliferation of dengue vectors and viruses. This review describes how climate, specifically temperature, affects the vectors' ability to cause and sustain outbreaks, and how the infectiousness of dengue is influenced by climatic change. The review is focused on the core concepts and frameworks derived in the area of epidemiology of mosquito-borne diseases and outlines the sensitivity of vectorial capacity and vector-to-human transmission on climatic conditions. It further reviews studies linking mathematical or statistical models of disease transmission to scenarios of projected climate change and provides recommendations for future research directions.

Keywords: Aedes; arbovirus; climate; climate change; dengue.

Figure 1.. Temperature dependence of vectorial capacity parameters.

Adopted from Liu-Helmersson et al. [5]: extrinsic incubation period (n_m: top left), mortality rate (µ_m: top right), biting rate (a: middle left), infection probability (b_mi: middle right), transmission probability (b_mt: bottom left), and probability of human infection (b_h: bottom right).

Figure 2.. Graphical illustration of a compartmental transmission model with dynamic vector and human populations.

Subscript m and h refer to mosquito and human, respectively, S meaning infected, E exposed, I infected, R recovered and Eg: egg, La: larvae, and Pu: pupae. Transition rates between the different compartments in the model are regulated by the rates indicated in between the compartments. Mortality and birth rates are not marked in the figure.