Maricopa County 2021 West Nile Cases Blow Away Previous Record

PHOENIX, AZ — The number of West Nile virus cases reported in humans in Maricopa County this year has more than doubled the previous record.

As of Friday, the Maricopa County Department of Public Health reported 847 cases in the county and 62 deaths. The previous record for human cases in the county was 355, set in 2004, as reported by ABC 15.

These numbers are in sharp contrast to last year when the county only had three confirmed human cases of West Nile virus and one death.

One major factor in the sharp increase in cases this year is the more favorable weather for mosquitos compared to last year. 2020 was one of Phoenix's driest years on record, with very little Monsoon rain, while this year was wetter than normal.

Previous annual West Nile virus human case counts, according to county health department records:

• 2011: 50 cases and two deaths
• 2012: 98 cases and four deaths
• 2013: 52 cases six deaths
• 2014: 93 cases and 12 deaths
• 2015: 62 cases and two deaths
• 2016: 63 cases and five deaths
• 2017: 93 cases and six deaths
• 2018: 24 cases and six deaths
• 2019: 155 cases and 17 deaths
• 2020: Three cases and one death

West Nile virus first came to Arizona in 2003, according to the Arizona Department of Public Health. People become infected via a bite from a mosquito carrying the disease, but it is not transmitted from human-to-human.

The state health department has some tips for avoiding West Nile virus, the most effective of which is preventing mosquito bites. You can do this by using an EPA-registered insect repellant and having intact screens on windows and doors. Wearing long sleeves and pants can also protect you from bites.

You can help prevent mosquitos from breeding near your home by getting rid of standing water where mosquitoes lay their eggs. Even a small amount of standing water like in a flower pot or any upturned object that holds water is a potential mosquito breeding ground. You can treat standing water that you can't remove with larvicides that are usually are available at hardware stores, the state department of health advised.