Newswise — In the past several decades, rapid urbanization has created new habitats and may alter the conditions of habitats for mosquitoes that can pass potentially fatal diseases to humans. In urban areas around the world, researchers are finding more mosquito larval habitats for species responsible for the spread of infectious diseases like yellow fever, dengue, chikungunya, and Zika.
Species like yellow fever mosquito Aedes aegypti and Asian tiger mosquito Aedes albopictus – considered the most invasive in the world – have emerged in Southern California in recent decades, and researchers are now looking for ways to guide surveillance and control efforts.
As part of their recent study published in Scientific Reports, Guiyun Yan, PhD, professor of population health and disease prevention with the UCI Program in Public Health, and Xiaoming Wang, PhD, a postdoctoral fellow studying under Yan, aimed to investigate this phenomenon in Orange County. To determine the effects of urbanization on the spread of invasive mosquitos like Ae. aegypti and Ae. albopictus in the region, Yan and Wang examined local breeding sources, particularly the underground storm drainage systems that are extremely abundant and hard to access but can potentially serve as existing habitats for mosquitoes.
Their study showed the rapid spread of the Ae. aegypti mosquito in Orange County over the past several years. It also found that underground storm drainage water collected in the summer completely inhibited larval development for both aedes species, but was well suitable to Culex quinquefasciatus, the primary vector of West Nile virus and the most abundant species of mosquito in Orange County.
“Our study demonstrates that the impact of urbanization on the ecology of disease vectors should be closer looked at,” said Yan. “Vector species responded very differently to the environmental changes. We need to carefully monitor the impact of our changing environments, which will help us better determine what those changes can mean to the ecology of disease vectors.”
Wang also noted, “it was a successful collaboration between UC Irvine Public Health and local public health agencies to look into the emerging issues of vector-borne diseases during the rapid urbanization process in southern California.”
Results from Wang and Yan’s study can be used to enhance local mosquito surveillance programs and assessments on the impacts of urbanization.
The study was conducted in partnership with the Orange County and San Gabriel Valley Mosquito and Vector Control Districts, with additional support from the Pacific Southwest Center for Excellence in Vector-Borne Diseases. Funding for the work came from the U.S. Centers for Disease Control and Prevention, and the UCI Chancellor’s Fellow Fund.