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May 11 2015 – Aedes Aegypti Mosquito Found in Alameda County

HAYWARD – The Aedes aegypti mosquito has been detected in an industrial area in the city of Hayward by the Alameda County Mosquito Abatement District.  This mosquito is not native to California and has the potential to transmit several viruses not currently found here, including dengue, yellow fever, and chikungunya.  Aedes aegypti has now been detected in 10 counties in California, including San Mateo.

Aedes aegypti is a small (about 1/4 inch), dark mosquito with white markings and banded legs.  This particular type of mosquito may be active during dusk and dawn, but most often bites during the day and often bites indoors.

The Alameda County Mosquito Abatement District has increased surveillance efforts for Aedes aegypti throughout the county and are investigating the source of this introduction.  Door-to-door property inspections for mosquito breeding sources and treatments for larval mosquitoes have also been intensified in the area surrounding the Aedes aegypti detection.

“Our primary goal is to eliminate this mosquito population so it does not spread,” said District Manager Jan O. Washburn.

To assist in eradicating this mosquito and reduce the risk of being bitten by mosquitoes, Alameda County residents and visitors are urged to:

  • Report mosquito bites received during the day or sightings of any mosquitoes matching the Aedes aegypti description to the Alameda County Mosquito Abatement District.
  • Apply insect repellents that contain DEET, picaridin, oil of lemon eucalyptus, or IR3535.
  • Make sure that doors and windows have tight fitting screens that are in good repair to keep out mosquitoes.
  • Eliminate standing water and containers that can hold water from around the house.
  • Check for hidden bodies of water, such as wells, septic tanks, manholes, and clogged drains.
  • Get FREE mosquitofish for ornamental ponds, water features, and horse troughs from the Alameda County Mosquito Abatement District.
  • Clean and scrub bird baths, ornamental fountains, plant saucers, and pet water dishes at least weekly.
  • Maintain swimming pools or stock with mosquitofish.

To obtain additional information about the Aedes aegypti mosquito, the public can visit the Alameda County Mosquito Abatement website at or the California Department of Public Health website at  Residents can also pick up FREE mosquitofish at our District office from 7:30-4:30pm for their ornamental ponds, horse troughs, or neglected swimming pools.  We are located in Hayward at 23187 Connecticut St.  Our phone number is (510)783-7744.