There have been more measles cases in the United States the first five months of 2019 than there were in all of 1992, when the last large outbreak occurred, federal health officials said on Thursday, in part because of the spread of misinformation about vaccines.

The Centers for Disease Control and Prevention said Thursday that there had been 971 known cases of measles in the United States so far this year.

That is eight more cases than in 1992, the previous high since vaccines became widely used, when 963 cases were reported in the United States all year. And it is a sharp jump from last year, when just 372 cases were reported, the agency said. (Earlier Thursday, the C.D.C. mistakenly said that the previous high was in 1994.)

“Measles is preventable and the way to end this outbreak is to ensure that all children and adults who can get vaccinated, do get vaccinated,” Dr. Robert Redfield, the director of the C.D.C., said in a statement.