Medical Assistant Janet Casamichana gives a flu shot to a child in Coral Gables, Fla., in September. Measles cases nationwide rose to 1,958 this year as of Dec. 16. (Photo by Joe Raedle/Getty Images)

Measles case are continuing to grow, reaching 1,958 confirmed cases in 43 states through Dec. 16 and threatening to undo next year the United States’ status as a nation that has eradicated the disease, according to a report released Dec. 17 by the federal Centers for Disease Control and Prevention.

The increase of 46 cases in one week, including dozens more in South Carolina alone, raises concerns for holiday travelers.

Cases have now reached 803 in Texas, 182 in Arizona, 142 in South Carolina, 122 in Utah, and 100 in New Mexico this year.

West Texas has been the epicenter this year, but recently South Carolina has seen measles “spread quickly in unvaccinated households” in the Spartanburg County area, and 168 people were quarantined as of Dec. 16, according to the state health department.

The state urged employers to accommodate people with quarantine orders to help avoid more spread, warning that the disease is highly contagious for days before a person is aware of being sick.

Towns with low vaccination rates along the Arizona/Utah border also have seen recent outbreaks.

By July, national case numbers had already surpassed a 2019 outbreak, bringing this year’s caseload to the largest in 33 years. The last time there were more cases was 1992, when there were 2,126, according to the CDC report.

The continued outbreak, reflecting a worldwide increase in the disease but also a rise in vaccine hesitancy that has been encouraged at times by U.S. Secretary of Health Robert F. Kennedy Jr. threatens the hard-won measles eradication declared in 2000 for the United States.

The status has already been taken away from Canada, where the Pan American Health Organization found an outbreak lasting 12 months invalidated the “eradicated” status, and the United States faces an assessment next year. The CDC maintained in November that it was still possible to eliminate measles in the U.S. by ensuring every child has two doses of vaccine, but vaccination rates have been falling further away from the 95% minimum rate that limits spread.

Even as cases have risen this year, the CDC has communicated less about the highly contagious disease on social media, according to Johns Hopkins University research published this month.

The agency posted 10 times on social media this year between January and August, compared with an average of 46 times in the previous four years, according to the report, despite a rising number of cases.

Ruth Lynfield, Minnesota state epidemiologist, said vaccine hesitancy may not be the whole story of low vaccination rates, in a video interview published Dec. 16 by Contagion, an infectious disease news service. Minnesota has 26 measles cases this year, down from 70 last year.

“Overall, there is vaccine confidence. Ninety-two percent of our kids [nationally] are vaccinated against measles. However, in particular communities, that number can be quite low,” Lynfield said. “One of the reasons is not that people may be vaccine hesitant, but they have other priorities.”

Physicians can counteract some of the low rates by gaining trust and listening to concerns, she said, and also just by making things simpler with reminders and easy choices.

“One thing we can do is ensure that we can make it as simple and convenient as possible for parents and families to bring kids in to get vaccinated,” she said.

Stateline reporter Tim Henderson can be reached at thenderson@stateline.org.