Mosquitoes known to carry dengue and yellow fever were spotted flying all over the state, said California health department.

As the reports come in about the dangerous visitors of California, the California health department officials are doing all they can to kick the threat of dengue and yellow fever and keep Californians out of possible diseases.

A hunt for the Aedes aegypti, also called the yellow fever mosquito, has been launched by health experts not only in the San Mateo County where these mosquitoes were spotted but also in several Bay Area counties. The program does not only aim to find the mosquitoes but to manage its reproduction as well.

Alongside Aedes aegypti, Aedes albopictus, also called Asian tiger mosquito, was reported lingering in the Los Angeles County for more than three years and raised concerns of spread to other counties.

Experts said that though these tropical illnesses, dengue and yellow fever, are very unusual in California, these pests could inhabit in the state and pose great threat to humans.

"We don't really have yellow fever here at all, and the only dengue fever cases are imported," said Deborah Bass, a spokeswoman for the Contra Costa Mosquito and Vector Control District, to Pentagon Post. "What we have now, with these mosquitoes, is a mechanism for transmission."

As of the moment, health officials said that the chances of being bitten and getting sick of dengue and yellow fever are just small.

Dengue and yellow fever are acquired through mosquito bites only. It cannot be transferred from human-to-human. So as long as there are no mosquitoes carrying such viruses, there will be no risk of spread.

Aside from managing the decreasing number of the sick persons platelet count, there is really no specific treatment. However, people should be warned that symptoms of dengue include fever, headache and intense muscle, joints, and bone pains. In exaggerated cases, some patients' gums bleed.

On the other hand, though there is a vaccine for Yellow Fever, in severe cases, it can still cause bleeding and shock, which can lead to death. Symptoms of yellow fever, like dengue, also include fever, headache and body ache.