Measles Cases Confirmed in Three Bay Area Counties: Alameda, San Mateo and Santa Clara

The number of measles cases in California has grown to 63 since the end of December, and the disease has now shown up in three Bay Area counties, state health officials said.

Of the 63 cases in the state, Dept. of Health Director Dr. Ron Chapman said 42 cases have been linked to an initial exposure at Disneyland or Disney California Adventure Park in Anaheim in mid-December, including five Disney employees. Of the seven Bay Area confirmed measles cases, three people in Alameda County contracted the disease while visiting Disney, according to the health department. The people who have measles in San Mateo and Santa Clara counties are not related to the Disney outbreak, health officials said.

Vaccination is key to preventing measles, which had been eradicated in the United States in 2000, Chapman said. State health officials determined that 34 of the 59 measles patients had vaccination documentation. Of those 34, 28 were unvaccinated, one had received one dose and five had received two or more doses of Measles, Mumps and Rubella (MMR) vaccine.

The California measles patients live in 11 health jurisdictions, including three Bay Area counties.

  • Alameda County has 5 cases, 3 linked to Disney parks
  • San Mateo County has 1 case, not linked to Disney parks
  • Santa Clara County has 1 case, not linked to Disney parks

In Southern California, Los Angeles, Orange, Riverside, San Bernardino, San Diego and Ventura counties, as well as the cities of Long Beach and Pasadena have seen measles cases.

Outside California, measles cases linked to the Disney parks have appeared in Mexico (one case), Utah (three cases), Washington (two cases), Colorado (one case) and Oregon (one case), according to the California Department of Health.

A Kaiser study released this week found that growing numbers of California schoolchildren are not being fully vaccinated. The rate of parents filing “personal belief exemptions” to allow their children into school without being fully immunized has doubled since 2007.

Five geographic clusters, including Napa and Sonoma counties, have especially large rates of under-vaccinated children. In some clusters, up to 23 percent of children are not fully vaccinated, according to the study.

In Southern California, where the majority of cases in the current outbreak have been reported, several schools, including Huntington Beach High School in Orange County, have had to tell about two dozen unvaccinated children to remain home when a case was found in a student. The incubation period for measles is as long as three weeks.

Symptoms of measles begin with fever, cough and runny nose and red eyes and within a few days a red rash appears, usually first on the face and spreading downward to the rest of the body. The disease is highly infections and spread through the air.

More information on measles symptoms and how to prevent its spread from the California Department of Public Health.

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