NEW YORK - U.S. measles cases have surged again, and are on pace to set a record for most illnesses in 25 years.
Health officials on Monday said 555 measles cases have been confirmed so far this year, up from 465 as of a week ago.
While 20 states have reported cases, New York has been the epicenter. Nearly two-thirds of all cases have been in New York, and 85 percent of the latest week's cases came from the state.
Most of the New York cases have been unvaccinated people in Orthodox Jewish communities.
Currently, the 2019 tally is the highest since an outbreak in 2014 that saw 667 cases. Many of the cases in the U.S. in 2014 were associated with cases brought in from the Philippines, which also experienced a large measles outbreak. The most before the 2014 outbreak was 963 cases in 1994.
The Centers for Disease Control and Prevention says that one out of every 20 children with measles gets pneumonia, which is the most common cause of death from measles in young children.
According to the European Centre for Disease Prevention and Control, there were 35 fatalities reported in European Union countries in 2018. There have been no reports of any deaths from the disease in the United States this year or last.
Measles first became a notable disease in the United States in 1921, requiring U.S. health care providers and laboratories to report all diagnosed cases. According to the CDC, there was an average of 6,000 measles-related deaths each year within the first decade of the disease being reported.
In 2000, measles was largely eradicated, having not been continually transmitted for a period of more than 12 months thanks to a highly effective vaccination program in the United States.
The CDC recommends that all children get two doses of measles vaccine.
The Associated Press contributed to this story.