PHOENIX — Maricopa County health officials have announced the season’s first death linked to West Nile virus, raising concerns about increased mosquito activity during Arizona’s monsoon season.
The victim, an older adult with preexisting medical conditions, died after complications from the virus, according to Dr. Nick Staab, chief medical officer for the Maricopa County Department of Public Health (MCDPH). The death marks a serious reminder that while most West Nile infections are mild, they can turn deadly for vulnerable groups.
“This unfortunate loss emphasizes the importance of prevention,” Staab said in a public health release. “Older adults and those with health issues are particularly at risk for severe outcomes from West Nile virus.”
Infections rising with summer storms
To date, 17 people have tested positive for the virus in Maricopa County this year. With the monsoon bringing more rainfall, the risk of infection is expected to climb.
The virus is primarily transmitted through mosquito bites, especially from mosquitoes that breed in stagnant water left by summer rains. Once infected, most people won’t experience symptoms, but about 20% develop flu-like effects, including fever, fatigue, joint pain, and headaches. In rare cases, the virus can lead to serious conditions like brain swelling (encephalitis) or inflammation of the spinal cord (meningitis).
Roughly one in every 150 infections results in severe neurological illness, which can include paralysis, tremors, seizures, or even death.
Officials urge prevention efforts
As mosquito season peaks, officials are reminding residents to take steps to reduce exposure and eliminate mosquito breeding grounds around their homes.
“Rain helps cool things down, but it also fuels mosquito populations,” said Staab. “It’s critical that residents take steps to protect themselves.”
Recommended safety tips from MCDPH include:
Using EPA-registered mosquito repellents that contain ingredients such as DEET, Picaridin, or oil of lemon eucalyptus.
Wearing long sleeves and pants outdoors, especially in the early morning and evening hours when mosquitoes are most active.
Fixing broken window and door screens to keep insects out.
Regularly emptying and cleaning containers that hold water, such as flowerpots, toys, birdbaths, and pet dishes.
Draining standing water from tarps, tires, buckets, and other outdoor equipment after rain.
Officials also stress the importance of community awareness: mosquitoes can breed in as little as a bottle cap’s worth of water, and shared spaces like apartment courtyards or irrigation ditches can harbor larvae if not properly maintained.
What to watch for
Although most people infected with West Nile virus show no signs of illness, symptoms — if they appear — can develop between two to 14 days after a bite. Milder cases may resemble the flu, while more serious ones could involve confusion, vision loss, numbness, or even coma.
Those who experience high fever, severe headaches, or neck stiffness are advised to seek medical attention immediately.
For ongoing updates and prevention tips, residents can visit www.maricopa.gov or contact their local vector control office.
