San Diego County vector control pilots were in the air Thursday making anti-mosquito larvicide drops over more than 30 rivers, streams, ponds and waterways.
The county says its Vector Control Program (VCP) has been making similar drops over local waterways once a month from April through October, San Diego’s peak mosquito season, for the last 15 years. The drops of solid, granular larvicide are aimed at killing mosquito larvae and stopping the spread of West Nile virus.
On the ground, the VCP treats more than 1,400 potential mosquito breeding areas by hand, including neglected swimming pools, and gives out free mosquito-eating fish. Staffers also test birds for West Nile virus.
The virus can be transmitted to people by Culex mosquitos, which are native to San Diego.
According to the county, around 8 of 10 people who contract West Nile never know it and never suffer symptoms. About 20 percent of infected people suffer mild flu-like symptoms. West Nile can be deadly but very rarely.
Three county residents have contracted the virus so far this year, but all contracted it outside of the county, the county said.