Epidemiology & Assessment

Aedes Aegypti Identified in Orange County

May 1, 2015

Aedes Aegypti, also known as the yellow fever mosquito, was identified by the Orange County Mosquito and Vector Control District (OCMVCD) in an Anaheim residence last week. OCMVCD is conducting surveillance in the area to assure that there is no wider spread of the mosquito. A. Aegypti can act as a vector to spread several viruses, including chikungunya, dengue, and yellow fever. There have been no locally-acquired cases of these viruses in Orange County or California, but an Orange County resident could acquire one of these infections while traveling and provide a viral source for A. aegypti upon return.


Measles in Orange County

April 20, 2015

The California Department of Public Health declared the measles epidemic associated with Disneyland to be over on April 17, 2015. From December, 2014 through February, 2015, 35 measles cases were identified in Orange County in the outbreak that started at Disneyland in mid-December 2014. Within California, 131 measles cases are likely linked to this outbreak, affecting 14 local health jurisdictions.


Dengue and Chikungunya in Mexico and Latin America

March 27, 2015

Regions of Mexico and Latin America have experienced a recent increase in chikungunya and continued dengue
infections. Travelers visiting affected areas should take appropriate precautions for avoiding mosquito bites during the day and at night.



Certain communicable diseases are required to be reported to the local health department (see List of Reportable Diseases) as per the State of California Code of Regulations. Epidemiology and Assessment (E&A) unit's medical directors, public health nurses, and epidemiologists investigate individual cases and outbreaks of reported communicable diseases. We monitor disease trends, and often provide current statistics and other information to doctors, hospitals, the public and news media. We may also provide education or preventive treatment in some circumstances. Although other units handle reports of HIV/AIDS, tuberculosis (TB) or sexually transmitted diseases (STDs), we do monitor their trends in Orange County. For more information or to report a Public Health emergency 24/7 call 714-834-8180.

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