# Host Usage in Aedes aegypti from Houston, Texas, and Phoenix, Arizona, Using Third-Generation Sequencing Blood Meal Analysis

## TL;DR

This study uses advanced sequencing to analyze what animals Aedes aegypti mosquitoes feed on in Houston and Phoenix, revealing a wide range of hosts including humans, pets, and even reptiles.

## Contribution

The study introduces third-generation sequencing to accurately identify multiple hosts and rare host species in mosquito blood meals.

## Key findings

- Houston mosquitoes primarily fed on humans and pets, with occasional multiple blood meals.
- Phoenix mosquitoes showed broader host usage, including livestock, birds, and reptiles.
- Third-generation sequencing effectively identified multiple hosts and rare species like ectotherms.

## Abstract

The yellow fever mosquito, Aedes aegypti, is a vector of several viral pathogens that frequently cause human disease but many of these pathogens are not controlled by vaccination. Effective control of this mosquito is thus critical for reducing disease transmission, and better understanding of the ecology of this species helps to improve the efficacy of operational control. In this study, researchers used a deep sequencing method to examine host usage in two large US metropolitan areas, Houston, TX, and Phoenix, AZ, both with substantial Ae. aegypti infestations, using samples collected during standard surveillance activities. In Houston, we identified occasional multiple blood feedings by individual mosquitoes and that the primary host sources were humans and their pets. Results from Phoenix indicated broader host usage, including feeding on livestock, birds, and even reptiles. This study demonstrates the benefits of a deep sequencing method for disambiguating multiple host feedings and detecting the broad scope of host usage.

The ecology and establishment of Aedes aegypti in tropical, sub-tropical, and temperate areas makes them one of the most medically relevant mosquito species. While they have been reported to be highly anthropophilic, several studies indicate a broader host range. They also reportedly take multiple blood meals between gonotrophic cycles, which makes determination of host usage difficult when using common blood meal analysis methods. In this study, we examined host usage of Ae. aegypti in Harris County, Texas (Houston), and Maricopa County, Arizona (Phoenix), using a nanopore-based third-generation sequencing protocol to resolve host usage and multiplicity. Using this method, approximately 80% of samples from each location with evidence of blood feeding resulted in blood meal identification, with a single host blood meal identified in about 80% of samples and approximately 20% containing evidence of multiple blood meals. Overall, we observed a wide host range with human DNA being the most prevalent followed by feline (Felis catus) and canine (Canis lupus). We also identified avian, rodent, ungulate and even ectotherm usage by Ae. aegypti from Maricopa County. This study demonstrates the utility of a third-generation sequencing method to identify less common hosts, like ectotherms in Arizona, and to resolve multiple feedings which remain difficult to resolve by current Sanger-based methods.