Standing water from monsoons increases West Nile Virus risk

With monsoon season upon us, we can expect great bursts of rainfall at a moment’s notice.

In Maricopa, most of this water does not run into a storm-drain system as in larger cities. Instead, it is held by on-site retention systems throughout town. In many subdivisions, you can see culverts that direct water into common landscape areas that become small ponds during intense rainfalls.

“It is typical in many cities in the region to not have a storm-drain system,” said Heather Murphy, the county’s communications director for health services and animal control. “It would be more necessary if we received more rain like they do back east, where they can have as much in one day as we do all year.”

With the recent testing of the mosquitoes carrying the West Nile Virus, the county has fogged Maricopa to kill the insects and their larvae to reduce the possibility of transmission. Murphy said traps are placed throughout Pinal County that capture mosquitoes to find ones that are infected.

Monsoons increase the risk of exposure to the West Nile Virus by creating standing water, which is necessary for mosquitoes to breed.

“Mosquitoes will breed anywhere (there is standing water), and it doesn’t take much,” said Murphy. “Birdbaths, tires, a pool that doesn’t have a circulation system; they can easily become a breeding ground.”

Murphy said there could be more fogging as rainfalls come throughout the summer.

Some people can get bit and not show any symptoms, Murphy said, while for others it can be potentially fatal. Arizona Department of Health Services has not had any reported fatalities this year, but there were 14 fatalities last year.

If there is another detection of West Nile, the county will issue notifications on what areas will be fogged.