First O.C. mosquitoes test positive for the Saint Louis Encephalitis virus

Garden Grove, CA. The Orange County Mosquito and Vector Control District (OCMVCD) has confirmed the first mosquito samples to test positive for Saint Louis encephalitis (SLE) in Anaheim and Westminster. The mosquitoes were collected from Old Bolsa Chica Road in Westminster and in the area of Dale Ave and Orange Ave in Anaheim. OCMVCD has not seen SLE positive mosquito samples in these areas since 1987. OMCVCD staff will conduct additional mosquito surveillance and canvass the area to look for additional mosquito breeding sources.

“This is the first detection in these areas in three decades. We are encouraging residents to take the necessary precautions to keep themselves and their families safe. The best way to protect yourself from mosquito bites is to discard any standing water around your home to eliminate potential breeding sources,” said OCMVCD Public Information Officer, Heather Hyland.

Saint Louis encephalitis (SLE) is a viral disease spread to people by the bite of an infected mosquito. Most people infected with SLE virus have no apparent illness. Initial symptoms of those who become ill include fever, headache, nausea, vomiting, and tiredness. Severe neuroinvasive disease (often involving encephalitis, an inflammation of the brain) occurs more commonly in older adults. In rare cases, long-term disability or death can result. There are no vaccines to prevent nor medications to treat SLE. There are no confirmed cases of human infection at this time in Orange County.

Residents should take the following precautions to help reduce the chances of getting bitten by mosquitoes:
• Dump and drain any containers filled with water at least once a week
• Clean and scrub bird baths and pet water bowls weekly
• Dump water from potted plant saucers
• Do not transport or share plant stems rooted in water
• Drill a hole or puncture containers to eliminate standing water
To prevent mosquito bites, the District offers the following tips:
• Apply mosquito repellents to exposed skin before going outdoors; reapply as recommended
• Wear repellent containing DEET®, Picaridin, IR3535, or oil of lemon eucalyptus
• Close all unscreened doors and windows to prevent mosquitoes from entering your home or space; repair broken or damaged screens
• Wear long-sleeved shirts and long pants, and opt for lighter-colored clothing
Visit ocvector.org to learn more about what you can do to prevent mosquito breeding in and around your property.