Human Blood Feeding by Aedes aegypti (Diptera: Culicidae) in the Florida Keys and a Review of the Literature

Abstract

Aedes aegypti L. is considered to have a proclivity for feeding on human blood even when other hosts are available. However, few studies have demonstrated host use by this mosquito in the continental United States, where local transmission of dengue, Zika, and chikungunya viruses has been recently documented. This study investigated the bloodmeal sources of female Ae. aegypti in the subtropical city of Key West and the surrounding county in Florida with the goal of identifying preferred hosts. Blood-engorged Ae. aegypti mosquitoes were collected from BG Sentinel traps used as part of a routine surveillance program in the Florida Keys (Monroe County, Florida). Bloodmeal samples were analyzed using PCR assays, sequencing, and comparison with reference sequences in GenBank. Aedes aegypti females from Key West fed predominantly on humans (79.6%) and did not differ statistically from females collected from the rest of the Florida Keys (69.5%). Culex quinquefasciatus Say (Diptera: Culicidae), considered a host generalist, was collected and analyzed from the same sites for comparative purposes. Females of Cx. quinquefasciatus fed predominantly (70.7%) on birds and nonhuman mammals in the Florida Keys, corroborating the validity of molecular assay breadth and demonstrating that given the same group of available hosts Ae. aegypti selects humans. Our results indicated that Ae. aegypti has a high rate of human-biting in a subtropical area within the United States, supporting its role in recent local transmission of dengue and other viruses.

Tropicalization of temperate ecosystems in North America: The northward range expansion of tropical organisms in response to warming winter temperatures

“…The tropical "southern house mosquito," Culex quinquefasciatus, a vector of many human and wild/domestic animal pathogens (e.g., St. Louis encephalitis, West Nile virus, Western equine encephalitis, possibly Zika virus) occurs from California to Florida but has been gradually expanding northward (Hahn et al, 2015;Turell et al, 2001). Although this mosquito species will occasionally feed on human blood, it prefers to feed on animals (Pruszynski et al, 2020). Over the past several decades, the two most important mosquito vectors for dengue, Zika, chikungunya, and yellow fever-Aedes aegypti and Aedes albopictus-have been expanding their ranges worldwide (Gubler, 2002;Lambrechts et al, 2010;Roth et al, 2014).…”

The Extrinsic Incubation Period of Zika Virus in Florida Mosquitoes Aedes aegypti and Ae. albopictus

“…Ae. aegypti exhibit gonotrophic discordance and are highly anthropophilic meaning they strongly prefer to feed on human blood [33][34][35]. The anthropophilic nature may influence the likelihood of a vector feeding on an infected human host during an outbreak and thus, increases the likelihood of horizontal and vertical transmission of ZIKV [6].…”

Dataset for Aedes aegypti (diptera: Culicidae) and Culex quinquefasciatus (diptera: Culicidae) collections from key West, Florida, USA, 2010–2020

“…In the data set, these traps are noted with a ‘ND’ in the collection columns. There are three published articles that also include these data [1] , [2] , [3] .…”