Measles Activity in California 202ā4 ā As of April 27, 2024
As of April 27, 2024, 6 confirmed measles cases have been reported in California. These data are provisional and subject to change.
CDPH will update case counts weekly.
Table. Reported Measles Cases by Week of Rash Onset ā California, 2024 ā
ā1/6/2024
| ā0
|
ā1/13/2024
| ā0
|
ā1/20/2024
| ā0
|
ā1/27/2024
| ā0
|
ā2/3/2024
| ā2
|
ā2/10/2024
| ā0
|
āā2/17/2024
| ā0
|
ā2/24/2024ā
| ā0
|
āā3/2/2024
| ā2
|
ā3/9/2024
| ā0
|
āā3/16/2024
| ā1
|
ā3/23/2024
| ā0
|
āā3/30/2024
| ā1
|
āā4/6/2024
| ā0
|
āā4/13/2024
| ā0
|
ā4/20/2024ā
| ā0
|
ā4/27/2024ā
| ā0
|
Outbreaks
While high levels of immunity in the general population ultimately limit measles outbreaks, measles readily spreads in communities and social networks with lower coverage.
In December 2014āApril 2015, at least 131 California residents were infected in a large measles outbreak associated with Disneyland; the outbreak also infected residents of six other states, Mexico, and Canada.
In 2019, there were 73 confirmed measles cases in California, including 41 cases associated with six outbreaks (defined as 3 or more cases). Of the six outbreaks, five were linked to patients with international travel, while one had an unknown source. The largest outbreak consisted of 21 cases and involved multiple generations of transmission in a health care setting. The other five outbreaks involved from 3 to 5 cases.
Case counts for 2012ā2018 are available in the Vaccine-Preventable Disease Summaries. Case counts for 2019āā2021 are available in the Vaccine-Preventable Disease Annual Report. There were no measles cases reported in California in 2022 and 4 measles cases were confirmed in California in 2023.
For information on measles cases and outbreaks nationwide, please see the CDC Measles Cases and Outbreaks.