"Many of the young Hmong children are not immunized, either because of cultural reasons or lack of education," said Merelyn Boren, supervising public health nurse for Fresno County. "We've focused our outreach efforts on these people, going door-to-door in the apartments."
Other counties are conducting similar efforts, but experts say that reaching parents of preschool children--the highest-risk group--is difficult because the children are not yet in school.
"This thing is not going to go away until parents get their children immunized," said Dr. Steve Waterman, chief of communicable diseases for Los Angeles County. "The trouble is, many of these kids are not in day-care centers, are not getting systematic medical care, or have parents who are nervous about coming into our clinics. We just can't find them."
State officials say the timing of the epidemic is particularly distressing because of a financial pinch on California's immunization program. Dales of the Health Services Department said the state will have 25% less than needed to spend on measles and other vaccinations this year.
"What that could mean is we may have to close down the clinics in September and tell people to come back in 1991," Dales said. "Considering that the public health program (provides vaccinations for) one-third of the state's children, that could be a very big problem."
Times staff writers Greg Johnson and Lanie Jones contributed to this story.