West Nile Virus Positive Mosquito Sample Found in Lake Balboa

This is an email notification that the Greater Los Angeles County Vector Control District (GLACVCD) has confirmed the first mosquito sample to test positive for West Nile virus (WNV) in Lake Balboa this year. This positive sample was detected in mosquito traps in your community on July 8^th. District staff have placed notices in public spaces (e.g., parks, etc.) within a half-mile radius around trap locations to advise residents to take precautions when mosquitoes are present. To support these efforts, we have attached graphics that can be posted on social media and other communication channels to spread awareness.

For more information about WNV activity in California, please visit 2025 West Nile Virus Activity in California.

Important WNV Information

• WNV is transmitted to people and animals through the bite of an infected mosquito.
• 1 in 5 persons infected with the virus will exhibit symptoms.
• Symptoms include fever, headache, body aches, nausea, or a skin rash.
• Severe cases can lead to paralysis or even death.
• There is no human vaccine for WNV.

Mosquito Prevention and Protection 

Mosquito control is a shared responsibility, and residents must take an active role in reducing the threat of WNV in their neighborhoods by taking the following steps:

• Eliminate standing water in clogged gutters, rain barrels, discarded tires, buckets, watering troughs, or anything that holds water for over a week.
• Ensure that swimming pools, spas, and ponds are properly maintained.
• Change the water in pet dishes, birdbaths, and other small containers weekly.
• Wear insect repellent when outdoors where mosquitoes may be present.
• Report neglected (green) swimming pools in your neighborhood to GLACVCD.