The San Mateo County Mosquito and Vector Control District has detected invasive Aedes aegypti mosquitoes in the county. They were most recently found in late January in areas of Menlo Park.
Aedes aegypti is not native to San Mateo County. It is a small, day-biting mosquito that prefers to feed on humans. It is capable of transmitting several viruses, including dengue, chikungunya and yellow fever.
While these viruses are not currently transmitted in San Mateo County, they are periodically introduced by international travelers.
In the presence of a large population of Aedes aegypti mosquitoes, a single case of one of these diseases has the potential to become an epidemic, county health officials say.
The Vector Control District has been actively looking for the mosquito in areas of the county where Aedes aegypti has been detected. These efforts include door-to-door inspection of residential properties for standing water where mosquitoes can breed.
The Aedes aegypti mosquito lays its eggs just above the water surface in small containers, such as flowerpots, plant saucers, pet bowls, bottles and bird baths. As these mosquitoes can breed in amounts of water as small as a bottle cap, residents are reminded to survey their property and immediately eliminate all standing water.
Residents can reduce the chances of being bitten by Aedes aegypti or other mosquitoes by:
• Applying insect repellents that contain DEET, picaridin, oil of lemon eucalyptus or IR 3535 and following label instructions;
• Making sure that doors and windows have tight-fitting screens;
• Eliminating standing water and containers that can hold water from around the home;
• Reporting neglected swimming pools or other water sources;
• Wearing long-sleeved shirts and long pants when outdoors.
Anyone who is being bitten by mosquitoes during the day should report them to the San Mateo County Mosquito and Vector Control District (650) 344-8592 or by visiting www.smcmvcd.org.