top of page

First West Nile Virus Infected Mosquitoes Collected in 2017 by the San Gabriel Valley Mosquito and V

San Gabriel Valley, CA – May 09, 2017

Samples of mosquitoes collected from Bonelli Park in the City of San Dimas have tested positive for West Nile virus (WNV). This confirms that mosquitoes in the San Gabriel Valley are actively circulating the virus and people are once again at risk of being infected.

These are the first WNV-positive mosquito samples collected this year within the San Gabriel Valley Mosquito and Vector Control District’s boundaries. Mosquitoes were collected on May 05, 2017 in traps placed at Bonelli Park, located at 120 Via Verde Park Road in the City of San Dimas. The District is continuing with surveillance activities and control efforts throughout the San Gabriel Valley as it prepares for the seasonal increase in mosquito populations and WNV activity.


It is critical that residents remove all standing water on their property to prevent mosquito production. Mosquitoes lay their eggs on stagnant water such as neglected pools, buckets, miscellaneous containers, puddles, and ponds. Eggs can hatch and develop into biting adults in four to seven days.

Residents can protect themselves from mosquito bites by using mosquito repellents, wearing long sleeve shirts and long pants when outdoors between dusk and dawn, and ensuring windows and doors are properly screened to keep mosquitoes out.

Throughout the summer, basic protective measures should be followed:

  1. Wear mosquito repellent and protective clothing when outdoors while mosquitoes are active (especially around dawn and dusk).

  2. Regularly inspect property to identify and remove sources of standing water where mosquitoes lay their eggs and grow.

  3. Ensure doors and windows are properly screened.

  4. Report mosquito activity, sources of standing water, and green pools to the District at (626) 814-9466 or online at www.SGVmosquito.org.

Since its introduction in 2003, WNV has infected more than 6,000 people and caused 248 deaths statewide, according to the California Department of Public Health. West Nile virus is endemic in California and presents a risk to public health every year.

The District encourages the public to help identify WNV “hot spots” by reporting dead birds to the WNV Hotline at (877) WNV-BIRD ((877) 968-2473) or online at www.westnile.ca.gov.

bottom of page