Brain Injury Association of Arizona Warns of the Hidden Brain Injury Risks from West Nile Virus: Encephalitis and Meningitis
Phoenix, AZ — The Brain Injury Association of Arizona (BIAAZ) is raising urgent awareness about the serious neurological risks associated with West Nile Virus (WNV), including the potential for encephalitis — a dangerous inflammation of the brain that can lead to long-term cognitive impairment, disability, or even death.
West Nile Virus is a mosquito-borne illness that circulates in Arizona, particularly during the peak mosquito season from late spring through early fall. While most people infected with WNV experience mild or no symptoms, approximately 1 in every 150 people who become infected will develop a severe neurological infection such as encephalitis or meningitis, conditions that can directly impact the brain and central nervous system.
These neuroinvasive diseases can result in high fever, headache, disorientation, seizures, paralysis, long-term disability, or death, according to the Arizona Department of Agriculture.
In 2023, the Arizona Department of Health Services reported 82 confirmed and probable human WNV cases statewide, including 53 cases involving encephalitis or meningoencephalitis — underscoring the neuroinvasive potential of this disease. There were 13 fatalities reported that year linked to WNV infections.
In Maricopa County in 2025, public health officials confirmed multiple human WNV cases and at least one death, reminding residents that this virus remains a current and ongoing threat.
“West Nile Virus shouldn’t be dismissed as just a summer illness — for some Arizonans it can cross into the brain and cause life-altering injury,” said Carrie Collins, Director of the Brain Injury Association of Arizona. “Understanding the neurological risks and taking steps to prevent mosquito bites can protect not only your immediate health but also your long-term brain health.”
Because encephalitis and other neuroinvasive complications of WNV can result in brain injury, BIAAZ stresses the importance of prevention and education. We urge all Arizonans to take proactive steps to reduce mosquito breeding sites around their homes, use EPA-registered insect repellent, wear protective clothing, and follow local public health guidance.
For comprehensive information on mosquito prevention, bite avoidance, and resources on West Nile Virus, visit the Maricopa County Mosquito Toolkit.
Source Links:
https://www.maricopa.gov/4464/St-Louis-Encephalitis-West-Nile-Virus Maricopa County
https://www.azdhs.gov/documents/preparedness/epidemiology-disease-control/mosquito-borne/west-nile/data/west-nile-virus-az-2023.pdf?v=20230609 Arizona Department of Health Services
https://www.azdhs.gov/documents/preparedness/epidemiology-disease-control/mosquito-borne/west-nile/data/west-nile-virus-stats-2021.pdf Arizona Department of Health Services
https://agriculture.az.gov/pestspest-control/human-diseases/west-nile Arizona Department of Agriculture
About the Brain Injury Association of Arizona
The Brain Injury Association of Arizona is a nonprofit organization dedicated to providing support, education, advocacy, and resources for individuals and families affected by brain injury throughout Arizona.
Our mission is to improve the quality of life for survivors and help prevent brain injury through awareness and education.