Summertime is mosquito time, and this year they're carrying more than an itchy bite. Arizona is emerging as one of the country's biggest West Nile virus hotspots, making prevention more important than ever.
"West Nile is an infection from a virus that has the potential to cause long-term effects. But most people — up to 80% — have little to no symptoms," says Kim Olson Gibbs, MD, family medicine physician at HonorHealth. "You could be infected and not even know it after being bitten by an infected mosquito two to 14 days earlier."
That’s ok, she assures, since most infections are mild. Here’s what you need to know about the virus and what to do next if you have symptoms.
West Nile virus and how it spreads
West Nile is the leading mosquito-borne virus in America, affecting more than a thousand people each year. In most cases, it’s asymptomatic or mild, but in rare instances it can lead to neurological complications.
"Less than 1% of people will develop severe neurologic illness, which may include encephalitis (brain swelling) or meningitis, an inflammation of the membranes around the brain and spinal cord," Dr. Olson Gibbs explains.
According to CDC data, Arizona reported 32 human West Nile virus cases by early July of 2026, more than half of all reported U.S. cases and the highest number in the country this season.
Summer fatigue or something more?
About one-fifth of people who contract the virus develop mild symptoms that can mimic other summer bugs. Common West Nile virus symptoms include:
- Fever
- Headache
- Body aches
- Fatigue
- Skin rash
- Nausea
- Vomiting
- Diarrhea
While these symptoms can feel miserable, they can also resemble illnesses like the flu, COVID-19 or Valley fever. That's why it's crucial to talk with your primary care provider rather than trying to diagnose yourself.
If you experience seizures or have a high fever accompanied by severe headache, stiff neck, muscle weakness or confusion, head to an emergency room or your nearest HonorHealth Urgent Care location immediately. Our experts may order a blood test or spinal fluid test to detect West Nile virus, if medically appropriate.
Risks and treatment
Certain individuals face a higher risk of severe complications, including:
- Adults age 60 and older
- People with diabetes
- Individuals with high blood pressure
- Those with kidney disease
- People who are immunocompromised
Currently, there is no specific antiviral medication for West Nile virus. "Treatment is mostly supportive and aimed at reducing any discomfort," says Dr. Olson Gibbs. At HonorHealth, our teams work together to manage symptoms, prevent complications and provide intensive care if severe neurologic illness develops.
Your summer game plan: Avoid the bite
Dr. Olson Gibbs recommends taking small steps to protect yourself at home and beyond, especially during Arizona’s monsoon season when standing pools of water encourage mosquito breeding. "The good news is there are simple things you can do to lower your risk," she says.
- Apply an EPA-approved insect repellent before spending time outdoors.
- Wear long sleeves and pants outside at dawn or dusk, when mosquitoes are most active.
- Dump standing water from buckets, flowerpots, birdbaths and other containers after monsoon storms.
- Keep window and door screens in good repair to help keep mosquitoes outside where they belong.
With Arizona's mosquito season in full swing, prevention is always the best defense.