Epidemiology & Assessment

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.


Wound Botulism Associated with Heroin Use in Orange County

December 15, 2014

Three cases of presumed botulism associated with heroin use have been reported in Orange County adults in the last month. All were hospitalized and two required intensive care unit admission. Wound botulism has been seen in injection drug users in California since the 1990’s, and botulism due to injection drug use now makes up three quarters of all wound botulism cases. Most persons with injection drug-associated cases are users of so-called “black tar heroin.”



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.

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