The county has stepped up efforts to eradicate a species of mosquito, Aedes aegypti, known for carrying yellow fever, from Menlo Park.
This image of the Aedes aegypti mosquito is from the Centers for Disease Control and Prevention.
Aedes aegypti is a 1/4-inch black and white mosquito, more commonly found in the southeastern United States than in California. It typically bites during the day and can potentially transmit several viruses, including yellow fever.
The goal is to get rid of eggs in containers that can hold water, such as saucers, buckets, jars, and pots, the San Mateo County Mosquito and Vector Control District said.
The Aedes aegypti species can survive as eggs in dry containers over the winter, then hatch as temperatures warm in the spring, according to the district.
Officials said the eggs may be destroyed by scrubbing with bleach or another household cleaner; adding sand to the container; or drilling holes in the bottom of the container to prevent water build-up.
Yellow fever and other illnesses associated with the mosquito have not been reported in California to date.
"While the current risk of disease transmission from this mosquito remains low, it's important to make every effort to eradicate this population and prevent the possibility of any future disease transmission," Dr. Scott Morrow, county health officer, said in a press release.
"The public can help by surveying around their house and neighborhood and eliminate even the smallest amount of standing water, since these mosquitoes lay eggs in water, just above the water line."
Three adult Aedes aegypti mosquitoes and 14 larvae have been trapped in Menlo Park since late August, according to the Mosquito and Vector Control District, suggesting that the invasive species is attempting to establish itself in the area.
Inspectors have searched more than 1,000 homes, collecting 246 larvae samples. Yellow fever mosquito eggs were found at four additional locations after the first egg was found on Aug. 23 at Holy Cross Cemetery off Santa Cruz Avenue.
Call the San Mateo County Mosquito and Vector Control District at 344-8592 to schedule an inspection.