Zika Virus Mosquito Vectors: Competence, Biology, and Vector Control

Abstract

Zika virus (ZIKV) (Flaviviridae, Flavivirus) has become one of the most medically important mosquito-borne viruses because of its ability to cause microcephaly in utero and Guillain-Barré syndrome in adults. This virus emerged from its sylvatic cycle in Africa to cause an outbreak in Yap, Federated States of Micronesia in 2007, French Polynesia in 2014, and most recently South America in 2015. The rapid expansion of ZIKV in the Americas largely has been due to the biology and behavior of its vector, Aedes aegypti. Other arboviruses transmitted by Ae. aegypti include the 2 flaviviruses dengue virus and yellow fever virus and the alphavirus chikungunya virus, which are also (re)emerging viruses in the Americas. This mosquito vector is highly domesticated, living in close association with humans in urban households. Its eggs are desiccation resistant, and the larvae develop rapidly in subtropical and tropical environments. Climate warming is facilitating range expansion of Ae. aegypti, adding to the threat this mosquito poses to human health, especially in light of the difficulty controlling it. Aedes albopictus, another highly invasive arbovirus vector that has only been implicated in one country (Gabon), is an important vector of ZIKV, but because of its wide geographic distribution may become a more important vector in the future. This article discusses the historical background of ZIKV and the biology and ecology of these 2 vectors.

Keywords: Aedes aegypti; Aedes albopictus; Flavivirus; Zika; vector competence.

Figure 1.

Maps showing the reported occurrence of Aedes aegypti by county between 1 January 1995 and March 2016 in the United States. Reported occurrence from 1 January 1995 through 1999 (A), from 1 January 1995 through 2004 (B), from 1 January 1995 through 2009 (C), and from 1 January 1995 through March 2016 (D), representing the best knowledge of the current distribution of this mosquito based on collection records. Counties shown in white had no reported Ae. aegypti presence records within the specified time period. Counties shown in yellow had Ae. aegypti presence records for 1 year within the specified time period, those shown in orange had 2 years of presence records within the specified time period, and those shown in red had ≥3 years of presence records within the specified time period. Adapted from Hahn et al [42].

Figure 2.

Maps showing the reported occurrence of Aedes albopictus by county between 1 January 1995 and March 2016 in the United States. Reported occurrence from 1 January 1995 through 1999 (A), from 1 January 1995 through 2004 (B), from 1 January 1995 through 2009 (C), and from 1 January 1995 through March 2016 (D), representing the best knowledge of the current distribution of this mosquito based on collection records. Counties shown in white had no reported Ae. albopictus presence records within the specified time period. Counties shown in yellow had Ae. albopictus presence records for 1 year within the specified time period, those shown in orange had 2 years of presence records within the specified time period, and those shown in red had ≥3 years of presence records within the specified time period. Adapted from Hahn et al [42].

Figure 3.

Locations of bioassay data for the organophosphates and pyrethroids, 2006–2015. Locations of populations that have been bioassayed (susceptibility and dose response, adult and larval) are shown for both insecticide classes, overlaid on maps of environmental suitability for Aedes aegypti and Aedes albopictus. Adapted from Moyes et al [86] and Kraemer et al [87].