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Everyone has a role in controlling mosquitoes
Mosquito RepellentThe arrival of Arizona’s monsoon season brings afternoon thunderstorms and rainfall, as well as an increase in mosquitoes. With mosquitoes comes the threat of diseases they can carry, including West Nile Virus and Zika.
West Nile Virus spreads to people primarily through the bite of an infected Culex species mosquito, while the Zika virus is carried by a species known as Aedes aegypti. Both mosquitoes are found in Maricopa County. Culex mosquitos are most active during nighttime hours, while the Aedes aegypti is known to bite all day long.
The responsibility for controlling mosquitoes lies with all of us. The single most important thing we can do is eliminate standing water on our property. Mosquitoes must have water to complete their life cycle. Rain and irrigation water can produce hundreds of thousands of mosquitoes if larvae are allowed to remain in stagnant water for as little as three days.
Chapter III, Regulation 2, of the Maricopa County Health Code is quite explicit about our obligation to control mosquito breeding areas: "No person shall cause, maintain, or within his control, permit any accumulation of water in which mosquitoes breed or are likely to breed. The owner, occupant, or person in control of any place where mosquitoes are breeding, or which constitutes a breeding place for mosquitoes shall take all necessary and proper steps to eliminate the mosquito breeding and to prevent its recurrence through the elimination of or the institution of necessary control measures at mosquito breeding sites.” Violation of the Health Code is a misdemeanor, punishable as provided by law.
It is important to keep swimming pools, spas and fountains clean and operational, eliminate standing water that can collect and breed mosquitoes and empty any buckets, wheelbarrows, pet dishes, wading pools, birdbaths, plant pots or drip trays at least twice a week. It also is important to keep good screens on windows and doors to keep mosquitoes out.
To avoid mosquito bites, use insect repellent containing DEET and wear long sleeves and pants when outdoors. When possible, wear light-colored clothing that can help you see any mosquitoes that land on you. Using yellow bulbs in porch lights instead of insect-attracting white bulbs also is recommended. Property owners may also elect to contract with a local pest control company for regular mosquito spraying and treatment, especially during the summer months.

Fight the Bite logoLocal government’s role
The Maricopa County Environmental Services Department has for years been implementing a surveillance program where they monitor hundreds of sites identified as mosquito breeding areas, plus proactively search for new or potential sites. They trap mosquitoes and work in conjunction with State health officials to test the mosquitoes for arboviruses, including Zika, and then eradicate breeding areas using the appropriate treatments.
A website maintained by the county,, provides an online form for reporting mosquito activity and green pools. The site also provides information on mosquito-related diseases, prevention, monitoring and fogging. Residents can also call the county's mosquito hotline (602-506-0700) to report concentrations of mosquitoes.
The City of Chandler has several areas of responsibility when it comes to mosquito control. Chandler’s Code Enforcement Division responds to complaints about green pools and works with the county to contact the owner and have the pool treated to prevent mosquito breeding. Our Parks Division works to eliminate breeding areas in City parks and our Streets Division works to maintain storm drains and City-owned retention basins so that water drains properly and doesn’t pond for long periods of time.
Retention basins are a frequent sight in Chandler neighborhoods and along City streets. In many cases, these basins double as small parks, greenbelts or open space. The City owns a number of retention basins, but the vast majority are owned and maintained by neighborhood associations, commercial developments and individual property owners. They are intended to capture stormwater runoff and often are connected to a storm drain that collects water from a street or parking lot.

To keep the water from ponding and stagnating, drywells are commonly constructed within the basins to allow the water to percolate into the ground. City Code requires all such basins to drain within 36 hours. If not maintained, drywells can become plugged with silt and debris, resulting in standing water and an increase in mosquito activity. For this reason, it is imperative that homeowner associations, businesses and residents maintain any drywells on their property.

Worries about Zika
Zika was first identified in Uganda in 1947. An outbreak in the Americas occurred in 2015 in northeastern Brazil and its spread has led the World Health Organization to declare a public health emergency, in part because a link has been identified between Zika and birth defects among infants of infected mothers.

The U. S. Centers for Disease Control and Prevention (CDC) says that about one in five people with the virus become ill, lasting several days to a week. Symptoms can include fever, rash, joint pain and conjunctivitis (red eyes). In addition, the CDC says there is sufficient evidence that the virus is a cause of microcephaly in newborns. There are no vaccines or specific treatment for Zika.
In a February article by the Associated Press, Harry Savage, chief entomologist with the CDC, said his best guess is that Zika infections transmitted within the U.S. will stay relatively small — much like Dengue fever, which averaged 25 cases per year from 2010 to 2015 — though he said he can’t be sure.

Health officials in Arizona are expressing confidence in their ability to quickly identify any Zika outbreak and effectively control its spread. In a June 8 interview with The State Press, an epizoologist with the Maricopa County Department of Public Health, Craig Levy, told the newspaper that although it is possible for a local outbreak to develop, the chances are slim, and the chances of a serious outbreak are even slimmer.
The Arizona Department of Health Services put out a news release in March following the first confirmed case of Zika in a Maricopa County resident; a woman who returned to Arizona after traveling to an affected area outside of the United States. The press release included the following statement by Cara Christ, MD, MS, director of the Arizona Department of Health Services:
"We have been expecting a travel associated case of Zika virus and we believe more infections are likely as people travel to and from areas where the disease is currently being transmitted. While this is a first, the risk of this virus spreading throughout Arizona is very low. Arizona's public health system has a plan in place and we are ready to rapidly respond."

For more information
Information about mosquito causing diseases and their prevention can be found online at For more information on Zika in Arizona, visit For information on Zika and pregnancy, visit To report mosquito concentrations or green pools, call the county’s mosquito hotline, 602-506-0700.