Invasive Aedes mosquitoes are not native to San Mateo County, California, or even North America. They do not belong in our ecosystems, and they can make people very uncomfortable because they bite during the day and even bite indoors. More importantly, they are a risk to human health because they can carry diseases that make people very sick, like Zika, chikungunya, dengue, and yellow fever.
Species of invasive Aedes mosquitoes are found in some areas of Arizona and California. One species, Aedes aegypti, has been found in San Mateo County before. This interactive map by the California Department of Public Health shows where they are currently found in our state.
The District has been working hard to get rid of invasive Aedes mosquitoes in our county, and has been very successful so far. The most recent time any invasive Aedes aegypti mosquitoes were found in San Mateo County was in May of 2015.
Although invasive Aedes mosquitoes have not been seen in our county recently, there is a high risk that they will be brought into our county again. These mosquitoes are spreading throughout California and have been found as close by as Fresno, Merced, and Madera Counties.
The District continues to conduct intensive surveillance throughout the county, but you can help out by reporting suspected invasive Aedes mosquito sightings. The sooner we know that these invasive mosquitoes have arrived in our county, the better chance we have of stopping them.
Join California in the Fight Against Zika - Don’t Bring Zika Home.
The Zika virus is transmitted through the bite of an infected mosquito and through unprotected sex with someone who is infected. Zika virus can also spread from an infected pregnant woman to her developing baby during pregnancy or around the time of birth. At this time, no one has been infected with Zika from mosquitoes in California. You are at risk if you or your sexual partner travel to areas with Zika, including Mexico.
