Vector Competence and Capacity ofCulex erraticus(Diptera: Culicidae) for Eastern Equine Encephalitis Virus in the Southeastern United States

Abstract

Field studies of the ecology of eastern equine encephalitis virus (EEEV; family Togaviridae, genus Alphavirus) in the southeastern United States have demonstrated that Culex erraticus (Dyar and Knab) is the most common mosquito at many enzootic sites and is often infected with the virus. However, the competence of Cx. erraticus for EEEV has not been explored in detail. Culex erraticus females were collected from the field and fed upon EEEV-infected chicks. The infected mosquitoes were provided honey for nutrition and to monitor for time to infectiveness. Of the mosquitoes that survived the 14-d postfeeding period, 89% were infected and 84% had evidence of a disseminated infection, though titers were generally low. EEEV was first detected in honey 6 d postinfection and was detected in samples collected from 94% of the mosquitoes with a disseminated infection overall. These data and others were then employed to estimate the relative vectorial capacity of Cx. erraticus at an EEEV enzootic site in Alabama. The vectorial capacity of Cx. erraticus at this site was 44% of Culiseta melanura (Coquillett), the accepted enzootic vector, suggesting Cx. erraticus may play a role in transmitting EEEV in areas where it is abundant and Cs. melanura rare.

Interactions between the invasive Burmese python, Python bivittatus Kuhl, and the local mosquito community in Florida, USA

“…quinquefasciatus are medically-important vectors of arboviruses and parasites. Culex erraticus is suspected to be an important bridge vector for the Eastern equine encephalitis virus [ 59 ]. In North America, Eastern equine encephalitis virus is circulated and amplified among bird populations by the primary vector, Culiseta melanura , which is ornithophilic and largely specializes on passerines.…”

Mosquito Community and West Nile Virus Risk on a National Guard Training Base in Oklahoma

“…Primarily a bird-feeding species that transitions to mammals later in the season, Cx. erraticus has been documented with natural infections of eastern equine encephalitis (EEE) virus and WNV (Harrison et al 2009, Mendenhall et al 2012, Mukherjee et al 2012, Godsey et al 2013, Bingham et al 2016. Culex erraticus is a potential bridge vector (Cupp et al 2003(Cupp et al , 2004Cohen et al 2009;Lindsey et al 2018) reported nonhuman cases of EEE in 4 counties and at least 1 human case along the Arkansas-Oklahoma border.…”

Diverse Defenses: A Perspective Comparing Dipteran Piwi-piRNA Pathways

“…The subclade distinctions between anopheline and culicine mosquitoes not only reflect broader geographical preferences but also reflects two prominent biological and genomic characteristics. Only a small handful of arboviruses have been identified to be vectored by anopheline mosquitoes, ONNV and Mayaro virus [ 53 , 54 ], whereas culicine mosquitoes are infamous for their prolific capacity to vector EEEV and WNV in Culex strains and Chinkungunya virus, Yellow Fever virus, Zika virus, and dengue virus in Aedes strains [ 55 , 56 , 57 , 58 , 59 ]. Coincidently, the genome sizes and repetitive element contents of culicine mosquitoes is a magnitude larger than an anopheline mosquito genome and Drosophilid genomes ( Figure 1 E).…”