PHOENIX — Maricopa County saw a large increase in West Nile Virus (WNV) infections, according to the Centers for Disease Control and Prevention.
In September 2021, public health officials in Maricopa County were notified that the WNV index, which measures the number of infected mosquitoes in the area, was substantially elevated.
The data released last week provides the most recent information made available regarding statistics of West Nile Virus.
During the 2021 period, a total of 1,487 cases were identified, 956 (or 64%) patients were reported to have neuroinvasive disease, and 101 (or 7%) died.
Maricopa County had the largest recorded WNV outbreak of any county in the U.S. It was also more than four times the number of cases reported than the previous largest outbreak in Maricopa County in 2004.
Complete data for 2022 is not yet available, but below are the number of cases for the previous three years, and the previous record year:
- 2004: 355 cases in humans
- 2019: 155 cases in humans
- 2020: three total cases in humans
- 2021: 1,487 cases in humans
Experts are offering tips on ways to fight the bite when it comes to mosquitoes.
- You should use an EPA-registered insect repellent and make sure windows and doors that you may leave open have insect screens.
- Long-sleeved shirts and long pants help keep mosquitoes away from your skin.
- Protect your home by eliminating standing water where mosquitoes lay their eggs.
- A small amount of water in a flowerpot, bucket, upturned children’s toys or any other potential basin can become a mosquito breeding ground.
- Standing water that can’t be discarded can be treated with larvicides that usually are available at the hardware store.
Maricopa County health officials are also providing tips on how to prevent mosquitoes from breeding:
- Don't allow any outside water to stand for more than four days.
- Change water in animal watering dishes at least twice a week.
- Immediately remove any water that collects on pool covers.
- Clear leaves and twigs from eaves, troughs, storm and roof gutters.
You can report mosquito issues to Maricopa County by clicking here.
Health officials say those experiencing flu-like symptoms and/or neurological symptoms should seek healthcare and can ask their provider for a West Nile virus test.
For more information on West Nile virus signs and symptoms, click here.
