Zika and chikungunya: mosquito‐borne viruses in a changing world

Abstract

The reemergence and growing burden of mosquito-borne virus infections have incited public fear and growing research efforts to understand the mechanisms of infection-associated health outcomes and to provide better approaches for mosquito vector control. While efforts to develop therapeutics, vaccines, and novel genetic mosquitocontrol technologies are underway, many important underlying ecological questions remain that could significantly enhance our understanding and ability to predict and prevent transmission. Here, we review the current knowledge about the transmission ecology of two recent arbovirus invaders, the chikungunya and Zika viruses. We introduce the viruses and mosquito vectors, highlighting viral biology, historical routes of transmission, and viral mechanisms facilitating rapid global invasion. In addition, we review factors contributing to vector global invasiveness and transmission efficiency. We conclude with a discussion of how human-induced biotic and abiotic environmental changes facilitate mosquito-borne virus transmission, emphasizing critical gaps in understanding. These knowledge gaps are tremendous; much of our data on basic mosquito ecology in the field predate 1960, and the mosquitoes themselves, as well as the world they live in, have substantially changed. A concerted investment in understanding the basic ecology of these vectors, which serve as the main drivers of pathogen transmission in both wildlife and human populations, is now more important than ever.

Global risk mapping for major diseases transmitted by Aedes aegypti and Aedes albopictus

“…Over and above vector competence, temperature is also known to affect mosquito physiology, development, survival, reproduction, and biting rate, which will affect the epidemiology of vector-borne diseases. The complexity of interactions among mosquito vectors, arboviral pathogens, and environmental drivers has been discussed by Shragai et al (2017), as well as by Alto and Lounibos (2013).…”

Estimating the effects of variation in viremia on mosquito susceptibility, infectiousness, and R0 of Zika in Aedes aegypti

“…albopictus is believed to be a secondary vector [12]. Although most cases of ZIKV infection are asymptomatic [5], 20% of individuals develop symptoms associated with Zika fever [13]. Currently, human viremia is not well characterized.…”

Spatial heterogeneity in the abundance and fecundity of Arctic mosquitoes

“…Mosquitoes (Diptera: Culicidae) are a diverse and globally ubiquitous clade of insects that transmit significant human disease and are important to the structure and functioning of many ecosystems (e.g., Fang 2010, Shragai et al 2017. In aquatic environments, immatures (larvae and pupae) are food for invertebrates (e.g., Culler and Lamp 2009), fish (e.g., Louca et al 2009), and birds (Pielou 1994).…”

“…Adult females are also parasites of vertebrates. Thus, it remains a challenge to understand the ecological mechanisms, and their interplay with the changing environment, that act on the immature and adult stages to determine abundance (Chaves 2017, Shragai et al 2017. Despite the global relevance of mosquitoes to humans and natural systems, data on basic mosquito ecology are often outdated or lacking.…”

“…Despite the global relevance of mosquitoes to humans and natural systems, data on basic mosquito ecology are often outdated or lacking. Thus, it remains a challenge to understand the ecological mechanisms, and their interplay with the changing environment, that act on the immature and adult stages to determine abundance (Chaves 2017, Shragai et al 2017.…”