The Role of Temperature in Shaping Mosquito-Borne Viruses Transmission

Abstract

Mosquito-borne diseases having the greatest impact on human health are typically prevalent in the tropical belt of the world. However, these diseases are conquering temperate regions, raising the question of the role of temperature on their dynamics and expansion. Temperature is one of the most significant abiotic factors affecting, in many ways, insect vectors and the pathogens they transmit. Here, we debate the veracity of this claim by synthesizing current knowledge on the effects of temperature on arboviruses and their vectors, as well as the outcome of their interactions.

Keywords: arboviruses; mosquitoes; temperature; vector-borne diseases; vectorial capacity.

FIGURE 1

This map shows the global distribution of five arboviruses (current or past local transmission). Little squares refer to the period of first documented detection in humans (virus introduction). Phylogenetic studies suggest an African origin for all five viruses (Braack et al., 2018).

FIGURE 2

Female mosquitoes acquire the virus during a blood meal on a viremic host (1). Then the virus infects the midgut epithelium from which it escapes and disseminates to peripheral tissues/organs (2a). The virus reaches the salivary glands (2b) in which it replicates prior to be released in saliva during a blood meal (3). The time between the ingestion of the virus and its presence in saliva is referred to as the EIP. Transmission cycles are influenced by multiple extrinsic environmental factors.

FIGURE 3

The vectorial capacity represents the number of potential infectious bites that a vector dispenses after the EIP is completed. It describes the efficiency at which a vector population transmits a pathogen in natural settings. Temperature is a key factor affecting major parameters in this equation.