Nation, County Keep an Eye on Measles

Measles has increased in the United States for the second straight year, with preschool children running the greatest risk of developing both the disease and its most serious complications.

In Orange County, Calif., according to Dr. Thomas Prendergast, the county’s epidemiologist, seven cases of measles were reported in 1984 and 14 in 1985. Through April of this year, nine cases were reported, he said Friday.

“Last year this time we had one case,” he said, adding that he expected reports on several more cases from last month.

The national Centers for Disease Control said Thursday that 2,813 measles cases were reported in 1985, up 9% from 1984 and 90% from 1983’s record low of 1,497 cases.

Children under 5 accounted for 30% of all U.S. measles cases in 1985, with an incidence rate of 47 cases per 10,000, according to the Centers for Disease Control.

“We’re always going to reflect national trends like that,” Orange County’s Prendergast said, “mostly because of the tourism” that brings people to Southern California from around the country. In addition, traffic back and forth from Mexico, where measles is more prevalent, adds to the risk of exposure, Prendergast added.

“The increased incidence of measles among preschoolers is a source of concern since the risk of serious complications . . . is highest in the youngest age groups,” the CDC said.

Those complications can include pneumonia and encephalitis--both of which can cause death in some cases--as well as middle ear infections, said Dr. Ron Davis, a CDC immunization specialist.

“It’s almost impossible to control measles after the fact,” Prendergast said, since the most communicable time is a four- to five-day period before the telltale rash appears.

Since the licensing of measles vaccine in 1963, the number of measles cases in the United States has plunged from nearly 500,000 a year.

And despite the increases of the last two years, measles remains rare, the CDC said. The 1985 case count represents just 0.6% of the yearly total reported before the advent of the vaccine.

In December of 1985 and January of this year, a rash of measles was reported at a grade school and junior high in Irvine, Calif. An investigation revealed that those who caught the disease had all been immunized, but that they had received inoculations between the ages of 12 and 15 months, when the vaccine is not most effective, Prendergast said.

Times staff writer Mark Pinsky contributed to this story.