Researchers Map Areas Of Arizona Where West Nile-Carrying Mosquitoes Are Most Abundant In Order To Reduce Human Infection Rates
Historically, mosquitoes in southern Arizona have never posed a significant disease threat, but this year the state saw an unprecedented surge in the number of reported West Nile virus cases. During 2019 alone, more than 170 people in Arizona contracted the West Nile virus from mosquito bites, 17 of whom died as a result of the disease. This makes Arizona the state with the highest number of West Nile virus cases by far, and surprisingly, the majority of victims contracted the disease in urban and suburban areas of Maricopa County.
Due to this abrupt and disturbing disease trend, researchers at Northern Arizona University have been collecting mosquitoes from Maricopa County and other urban portions of southern Arizona in order to determine which areas in the state see the greatest number and highest density of West Nile-carrying mosquitoes. The researchers are also hoping to better understand how infected mosquitoes arrived in the state in such large numbers. Unfortunately, the West Nile virus is now said to be a permanent part of southern Arizona’s ecosystem, so there is little to no hope at all that disease-carrying mosquitoes will be eradicated from the state.
According to genetic analysis, many West Nile virus strains are being found in Mosquitoes originating from southeast Maricopa County. This explains why West Nile infection rates were particularly high in the southeast valley this year, but since area-wide mosquito fogging is not feasible in populated areas, researchers must pinpoint specific sites where West Nile-carrying mosquitoes breed. According to Crystal Hepp, an evolutionary biologist at NAU, many infected mosquitoes are emerging near the intersection of Loop 101 and Loop 202 in Tempe. This did not come as a surprise to researchers, as shallow pools of water are littered throughout this area due to backup from the Salt River.
The largely residential town of Gilbert was also found to be a major source of West Nile-carrying mosquitoes, and this may be due to the significant amount of lawn irrigation and water-filled objects often found in yards. These sources of standing water provide disease-carrying mosquitoes with their primary breeding source. Hepp stated that if these areas of shallow and stagnant water are not removed within 72 hours, they become dangerous sources of mosquito-borne disease.
Do you make a point to remove standing water from your yard in an effort to reduce the mosquito population?