From Anonymous to Public Enemy: How Does a Mosquito Become a Feared Arbovirus Vector?

Abstract

The past few decades have seen the emergence of several worldwide arbovirus epidemics (chikungunya, Zika), the expansion or recrudescence of historical arboviruses (dengue, yellow fever), and the modification of the distribution area of major vector mosquitoes such as Aedes aegypti and Ae. albopictus, raising questions about the risk of appearance of new vectors and new epidemics. In this opinion piece, we review the factors that led to the emergence of yellow fever in the Americas, define the conditions for a mosquito to become a vector, analyse the recent example of the new status of Aedes albopictus from neglected mosquito to major vector, and propose some scenarios for the future.

The Role of Temperature in Shaping Mosquito-Borne Viruses Transmission

“…In its overall effects, temperature may have a profound impact on natural ecosystems of rural and sylvatic cycles. New serotypes or currently unknown viruses could emerge from wildlife and affect humans following ecosystem alterations related to temperature changes; forest cycles are breeding grounds of unknown viruses representing a bottomless source of pathogens threatening human health (Fontenille and Powell, 2020). Neglected arboviruses are expected to become increasingly important, with temperature as a determinant factor of emergence (Lorenz et al, 2017).…”

“…The concept of vector competence is integrated in a broader one that is vectorial capacity which is an epidemiological measure of the transmissibility of an infectious agent by a particular vector species/population in the field (Macdonald, 1957). The mathematical equation used to evaluate the vectorial capacity (Figure 3) includes the following parameters: vector-host ratio (m), mosquito biting rate on human (a), daily survival rate (p), infectiousness of the mosquito to the vertebrate host (b), susceptibility of the vertebrate host to the virus (c), extrinsic incubation period (n) and vertebrate host infectious period (1/r) (Fontenille and Powell, 2020). Factors influencing the vectorial capacity have been largely discussed (Kramer and Ciota, 2015); the most determining variables are mosquito survival rate and extrinsic incubation period (EIP).…”

Understanding the role of arthropod vectors in the emergence and spread of plant, animal and human diseases. A chronicle of epidemics foretold in South of France

“…However, the notoriety of Ae. albopictus, compared to its relatives, comes from the fact that it has moved out of its area of origin, becoming worldwide in 50 years, adapting perfectly to urbanization, temperate climates, and international transport, as well as being involved in several dengue and chikungunya epidemics [25].…”

“…Nevertheless, as compared to important viral vectors, such as aphids [99] and whiteflies [100], there are still significant gaps in our Figure 2. Encounter and compatibility filters, the example of yellow fever, from [95], and [25]. knowledge of vectors of bacterial pathogens [98].…”

“…Cependant, la notoriété d'Ae. albopictus, par rapport aux espèces proches, vient du fait qu'il a quitté sa zone d'origine et s'est mondialisé en 50 ans, s'adaptant parfaitement à l'urbanisation, aux climats tempérés et aux transports internationaux, et en étant impliqué dans plusieurs épidémies de dengue et de chikungunya [25].…”