Helicopter drops larvicide
A helicopter drops larvicide over a waterway in San Diego County. Courtesy County News Center

San Diego County will conduct its first larvicide drop of the year on up to 51 local waterways as part of a campaign to combat diseases spread by mosquitoes such as West Nile virus, it was announced Wednesday.

Aerial larvicide drops are carried out once a month between April and October each year, covering around 1,300 acres of mosquito breeding areas.

The routine helicopter drops will be conducted next Wednesday, and Thursday if necessary, according to a news release from the county.

County officials say the larvicide does not hurt people or pets.

Locally, larvicide drops have been conducted since the early 2000s when West Nile virus was first detected in the United States. Though the disease mainly affects birds, county officials say mosquitoes can pass on the disease by feeding on infected birds, then biting people.

According to the county, around three to four people have tested positively per year since 2017 and no virus detections have been seen in the county so far this year.

Residents were urged to report increased mosquito activity or mosquito breeding sources like unmaintained swimming pools and dead animals to the County Department of Environmental Health and Quality‘s Vector Control Program, which can be reached by calling 858-694-2888 or emailing vector@sdcounty.ca.gov.

City News Service contributed to this article.