Disease spreading mosquito species found in Hayward

HAYWARD, Calif. (KTVU) - A well-known but rarely seen, disease spreading exotic mosquito has taken up residence in Alameda County.

The aedes aegygti is a tiny mosquito that can spread some pretty nasty diseases including dengue, chikungunya and yellow fevers.

The species was detected for the first time in the Bay Area two years ago in San Mateo County. Now, this is its first ever appearance in Alameda County. Specifically, it was spotted in an industrial area of Hayward.

"Typically, the way they're introduced is in the egg form," said Environmental Specialist Erika Castillo with the Alameda County Mosquito Abatement District. She adds that the virtually undetectable, microscopic eggs are inadvertently brought in from overseas in baggage or on cargo ships.

The mosquitoes that hatch are disease-free and would need to bite something or someone with a disease to become a health danger.

"Fortunately, right now, in the United States we have very few people who have these diseases where a mosquito can bite them and take that blood with that virus and bring it to another person. So, the risk is extremely low," said Dr. John Schwartzberg, a professor at the UC Berkeley School of Public Health.

But it is possible someone who has traveled to a diseased area could bring it back here in their blood, and it can be spread.

"We just have to be sure to apply our mosquito abatement as it should be done," said Dr. Schwartzberg.

Now that we know they're here, the next step is to use traps where the species has been found. Then, go into that area with larvacides to eliminate them.

"We hope it's an early detection and that it's pretty localized, and we can eliminate it," says Castillo. "We ought to be doing, as individuals, everything we can do to decrease the population of mosquitoes," said Dr. Schwartzberg.

That means there should be no standing water for them to breed. When it comes to people saving gray water for plants and lawns, Castillo hopes you'll take some precautions. "We just ask that you keep it either screened or covered so adult mosquitoes can't get into it and lay their eggs," says Castillo.