Range of Aedes mosquitoes in US ‘uncertain’
Researchers found significant gaps in existing model-based predictions of Aedes mosquito distribution in the United States, reporting in a recent study that “the edges of the geographic range of these important species remain uncertain.”
“Aedes aegypti and Aedes albopictus mosquitoes are important vectors globally. Dengue, chikungunya, and Zika viruses, spread by A. aegypti and A. albopictus, have been imported by infected travelers into the contiguous United States many times in recent years,” Michael Johansson, PhD, a biologist in the CDC’s Dengue Branch, told Infectious Disease News. “Understanding where these mosquitoes live is critical to assessing and reducing the risk of introducing viruses into new areas.”
For their study, Johansson and colleagues identified previously published regional and global habitat suitability models for A. aegypti (n = 6) and Ae. albopictus (n = 8) and used the information to reproduce the models for the contiguous U.S. They then used county-level surveillance records to construct accuracy-weighted, probabilistic models to assess accuracy and uncertainty.
The comparison identified “areas of substantial uncertainty and specific areas where model-based predictions do not align with available data,” they wrote. For instance, models showed a high probability of A. aegypti in some areas — such as the Florida panhandle — where the mosquito has never been identified.
Johansson suggested that the maps can be updated by using more data and improved models. He explained that more field collections targeting Aedes mosquitoes in areas where there is a high level of uncertainty can improve the ability to differentiate areas where they are present and that new modeling efforts will be needed to leverage data and improve previous maps.
“In the end, improved maps mean better information for doctors, patients, public health agencies, and mosquito control districts to assess risk and reduce exposures to viruses that can be spread by these mosquitoes,” Johansson said. – by Caitlyn Stulpin
Disclosures: Johansson reports no relevant financial disclosures.