The spread of measles in the Southwest now constitutes the largest single outbreak since the United States declared the disease eliminated in 2000, federal scientists told state officials in a meeting on Monday.
The New York Times obtained a recording of the meeting. Until now, the Centers for Disease Control and Prevention had not publicly described the outbreak in such stark terms.
More measles cases were reported mostly in Orthodox Jewish communities in New York City and New York State in 2019. But health officials regard those as separate outbreaks, because they were fueled by multiple introductions of the virus by international travelers.
C.D.C. officials now view the spread of measles in Texas, Oklahoma and New Mexico as a single outbreak, Dr. Dan Filardo, who leads the agency’s task force for the measles response, told state health officials at the meeting.
“This is the largest outbreak in the U.S. since measles elimination was declared in 2000,” he said. The agency was sending seven additional officials to Texas, epicenter of the escalating crisis, he added.
Texas health officials have reported 624 cases since late January. Two young, unvaccinated girls have died, the first measles deaths in a decade in the country.
As of Thursday, the C.D.C. had reported 800 measles cases nationwide, but the current tally is likely to be higher because it takes time for the agency to collate state reports.
More than 20 separate outbreaks brought the national case count in 2019 up to 1,249, a figure that the country is likely to surpass this year.
The Department of Health and Human Services did not immediately respond to a request for comment.
About 70 percent of cases across the country are among children, with a median age of 8. About 11 percent, or 85 cases, have required hospitalization, most of them in Texas.
Nearly all infections are among people who are unvaccinated or whose vaccination status was unknown. Mennonite communities, which often have low vaccination rates, have been disproportionately affected.
Measles has also struck Mennonite communities in Ontario, Canada, and Chihuahua State, Mexico. The Canadian outbreak has climbed to nearly 1,000 cases since October, and the one in Mexico has surpassed 400 cases since the outbreak began earlier this year. One adult resident of Chihuahua has died, of measles.
“With ongoing weddings, large religious gatherings and celebrations to mark the 500th anniversary of Mennonite origins, we remain concerned about the possibility of additional spread of measles across North American Plains communities as the year goes on,” Dr. Filardo warned state officials.
The measles outbreak in 2019 ended only after an aggressive, 11-month public health campaign that involved hundreds of experts, more than $8 million in health department spending, and, in some parts of the state, mandated immunizations, Dr. Jane Zucker, an adjunct professor at SUNY Downstate School of Public Health who was involved in the response, said at a meeting of C.D.C. advisers last week.
Health officials managing this year’s outbreak are facing unexpected obstacles.
In a public meeting last week, Dr. David Sugerman, a C.D.C. senior scientist, said recent threats to local public health funding meant the agency was now “scraping to find the resources” to support those in Texas and other states grappling with outbreaks.
Last month, H.H.S. moved to cut billions of dollars allocated to local health departments. (A judge temporarily blocked the funding cuts after a coalition of states sued the Trump administration.)
And layoffs at the C.D.C. eliminated entire divisions of the National Institute for Occupational Safety and Health, who had been helping states ensure that their hospitals were equipped to treat patients with an airborne respiratory disease.
The response has also been hamstrung by muddled messaging from the country’s top health official, Robert F. Kennedy Jr., who has downplayed vaccinations and the seriousness of measles infections while promoting unproven treatments, like cod liver oil.
In West Texas, local doctors said measles patients delayed critical medical treatment in favor of staying home and treating themselves with some of the supplements Mr. Kennedy promoted.
On the call with state officials, C.D.C. scientists did not mention treatments and unequivocally endorsed vaccines. “As we all know, vaccination remains the best tool to prevent and respond to measles outbreaks,” Dr. Filardo said.
