Outbreaks of red measles have been confirmed in both Maryland and Virginia, and health officials for both those states are now urging parents to check their children immunization records to prevent a major outbreak.

Health officials throughout the nation have found that children immunization before their first birthday are probably not immune to the highly infectious virus-caused disease.

This, coupled with the fact that parents have apparently become less concerned about the need for immunization because of the declining incidence of measles outbreaks, has alarmed health officials.

"Many parents feel it is not important to have their children immunized. But they just don't understand that one out of every 1,000 children afflicted with red measles dies as the result," said Dr. Susan Mather, Prince George's County epidemiologist.

In Virginia, at Henry David Thoreau Intermediate School in Vienna, a dozen red measles cases were confirmed Thursday, according to the Fairfax County Health Department.

And just yesterday, another case was confirmed at Polk Elementary School in Alexandria. William Blair, director of student health services said, "We are pulling all the records of students not immunized and informing their parents."

District of Columbia health officials said they are testing a preschool-age child who they suspect had red measles.

According to Dr. Mather, parents and principals in Prince George's County schools objected when they had enforce an immunization vertification policy of the County School Board. There have been no reported cases of red measles in the county this year.

In Northern Anne Arundel County nearby, however, there have been eight red measles cases confirmed by blood test. The cases were reported among children enrolled in Linthicum Elementary School. Five of the children had documented histories of receiving measl es vaccination between 12 and 15 months of age and three other received their shot before their first birthday, a Maryland State health official said.

Two other outbreaks, one involving three children in a southeast Baltimore junoir high school and another involving an infant in another area of the city, have also been reported, the health official said.

The Potential serverity outbreaks here and across the nation has prompted the U.S. Center for Disease Control in Atlanta to alert all states about the problem. A CDC spokesman said the number of cases reported this year is 2 1/2 times higher for the same period in 1976. And in 1976, there were more cases reported than in any year since 1971.