The United States recorded 41 new cases of measles in the week ended May 31, taking the total cases for the year to 981 in the worst outbreak since 1992, federal health officials said on Monday.
The Centers for Disease Control and Prevention said the number of cases of the highly contagious and sometimes deadly disease rose 4% in the week ended May 31, from the previous week.
The United States declared measles eradicated from the country in 2000, but officials with the CDC warned on Thursday that the country risks losing its measles elimination status.
There were a total of 2,126 U.S. cases of measles in 1992, the CDC said in a statement.
The disease has spread mostly among school-age children whose parents declined to get them vaccinated.
Public health officials blame the resurgence on the spread of misinformation about vaccines.
“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,” CDC Director Robert Redfield said in a statement.
“Again, I want to reassure parents that vaccines are safe, they do not cause autism,” Redfield said.
When measles was declared eradicated in the United States in 2000, it meant the virus was no longer continually present year-round, although outbreaks have still happened via travelers coming from countries where measles is common.