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Zika, Yellow Fever and Dengue 

The mosquitoes responsible for transmitting Zika, yellow fever and dengue, have been detected in parts of Orange County.

The Aedes aegypti  (the yellow fever mosquito), Aedes albopictus (the Asian tiger mosquito) and Aedes notoscriptus (the Australian Backyard Mosquito) have been detected in Orange County. All three invasive Aedes mosquitoes bite aggressively during the day and lay their eggs in small containers of water.


Zika virus was first discovered in 1947 and is named after the Zika Forest in Uganda. In 1952, the first human cases of Zika were detected. For the most up to date information, regarding areas with risk of Zika, please visit the CDC's website. 

Because a  Zika infection during pregnancy can cause severe birth defects, pregnant women should not travel to areas with a high risk of Zika. 

For more information on symptoms, treatments and general information, please visit the CDC's website. 

Yellow fever

Scientists believe that yellow fever evolved in Africa around 3,000 years ago. Until the mid-1800s, scientists believed that yellow fever was spread by direct contact with infected people or contaminated objects. It wasn't until the 1900s that Reed Yellow Fever discovered that yellow fever was transmitted by the Aedes aegypti mosquito. 

For the most up to date information. and to see where yellow fever is occurring, please visit the CDC's website. 


Dengue emerged as a worldwide issue in the 1950s. Dengue is endemic in Puerto Rico and many popular tourist destinations in Latin America, Southeast Asia and the Pacific Islands. 

For the most up to date information and to see where dengue is occurring, please visit the CDC's website.