REGION — Arizona’s warm weather and summer rains create ideal breeding conditions for mosquitoes.
Health officials advise residents to protect themselves against biting mosquitoes and the viruses they transmit by keeping their populations down with preventative measures.
“Mosquitoes can be active year-round in parts of Arizona, but they are most abundant between March and October,” said Ray Falkenberg, public information officer for Cochise Health and Social Services. “Mosquito bites can be more than just annoying and itchy — they can spread viruses that make you sick or even cause death. Whether you are spending summer here at home or traveling in the United States or abroad, the very best way to stay healthy is to avoid mosquito bites in the first place.”
Through statewide surveillance efforts, mosquitoes are trapped from mid-July to mid-October and tested for viruses. In Cochise County, traps are set in 24 different locations, said Greg McQuaide, county public health emergency preparedness coordinator, who oversees the area’s surveillance efforts.
The mosquitoes are sent to the Arizona Public Health Laboratory in Phoenix every other week for testing to determine if they are carrying the disease, McQuaide said. “Along with testing for viruses, we’re looking at environmental and weather data and how that correlates with mosquito populations.”
The two most prevalent disease-carrying mosquito species in Arizona are Aedes Aegypti and Culex.
Aedes Aegyit mosquitoes can be infected with Zika Virus, Dengue Fever Virus and Chikungunya, while Culex carry West Nile Virus and St. Louis Encephalitis.
West Nile can be fatal to horses, but there is an effective vaccine that protects horses, with veterinarians recommending vaccinations be administered in early spring or early summer for optimum protection.
In 2017, two mosquitoes in Cochise County tested positive for diseases, one for West Nile Virus and one for St. Louis Encephalitis, McQuaide said.
“During the 2018 surveillance season, no positive mosquitoes were identified,” he said.
To date, Maricopa, Pinal and Yuma counties are the only counties reporting infected mosquitoes through the surveillance testing, with Maricopa as the heaviest hit area.
McQuaide advises residents to be responsible for eliminating areas of standing water on their property.
“Mosquitoes breed in water, so our peak mosquito season coincides with the monsoon season,” he said.
“The Aedes Aegypti mosquito is an opportunistic breeder, requiring as little as a bottle cap of of water to lay its eggs,” McQuaide said. “Be diligent about eliminating potential breeding sites around your home. Rinse out your bird baths, dog water bowls and horse watering troughs every other day. Turn water containers over to prevent water collection areas,” he said. Aedes Aegypti are found mostly in densely populated municipalities, as people are the insect’s primary meal source, he added.
“The Egypti are mosquitoes that feed on humans specifically. Their whole mission in life is to bite humans. And they are out feeding all times of the day.”
Culex mosquitoes typically breed in larger bodies of water, such as rivers, streams, lakes and ponds, and are found everywhere.
Unlike the Aegypti, they are morning and evening feeders and will bite most warm-blooded animals — dogs, cats, horses and humans.
McQuaide said the elimination of Culex mosquitoes is most effectively accomplished by using larvicides, which can be purchased at feed, hardware and big box stores.
While safe around pets, the larvicide is harmful to fish and amphibians.
“When you’re outside during mosquito season, stay covered up with light colored clothing,” McQuaide said. Cover your arms with long-sleeved shirts and your legs with long pants.”
Use insect repellents, even when skin is covered.
The most effective prevention against mosquito bites is the use of insect repellents.
“Other repellents work, but a 30 percent DEET insecticide is the most effective,” McQuaid said.
Make sure window and door screens are in good repair, with no holes.
“Summer months in Arizona are great for for all kinds of outdoor recreational activities,” McQuaid said. “We take mosquito prevention very, very seriously and urge residents to take the necessary precautions to protect themselves against mosquito bites. I want people to be aware, not afraid.”