Orange County health officials met in an emergency session this week after the latest measles tally showed the number of cases in the county had rocketed in the last few weeks.
There are now 21 confirmed cases of measles in Orange County, the most of any county in California and nearly five times the number of cases in the entire state at this time last year, health officials said.
Across the state, the numbers also moved forward, climbing to 49 cases by Friday. Last year, at this time, there were only four reported in the entire state.
In Los Angeles County, there were 10 reported case of measles, mostly involving children. There were also confirmed cases in Alameda, Santa Clara, San Mateo, Contra Costa, Riverside and San Diego counties.
Health officials renewed their call for children to get vaccinated, and expressed concern that increasingly some parents are electing to bypass the vaccine, fearing its side effects.
"This dramatic jump is a reminder to get fully vaccinated," says Dr. Ron Chapman, director of the California Department of Public Health.
Among the new cases, 11 patients had traveled outside of North or South America, visiting parts of the world where outbreaks are actively occurring or where the illness is still widespread. Of those who did not travel out of the United States, 30 had contact with known measles cases, three had contact with international travelers, and five are being investigated to track potential sources, officials said.
Medical officials said immunization has kept preventable childhood diseases, including measles, at record lows in the last two decades. By 2000, measles was considered to have been essentially eradicated in the United States.
But the number this year indicates that it is again a health concern.
"We want parents to have an accurate understanding about how safe immunizations are and how dangerous vaccine-preventable diseases can be to their child, family and community, said Dr. Gil Chavez, deputy director of the state health department's Center for Infectious Diseases.
Doctors recommend that children get their first dose of MMR (measles, mumps and rubella) vaccine between 12 and 15 months. The second dose is usually given before kids enter kindergarten between ages 4 and 6.
Infected patients remain contagious for about eight days — four days before a rash starts and four days after. Symptoms may include ear infections, diarrhea and pneumonia. Death may occur in severe cases.