Risk of mosquito-borne diseases in San Mateo County in low, but you may be at higher risk if you travel to other areas of the state, country, or world. If you’re infected with a mosquito-borne illness while traveling, there is a risk you could pass it on to local mosquitoes once you return home, and a local outbreak could occur. These tips will help you protect yourself and others from mosquito-borne illnesses during and after travel.