Measles infections continue to spread across the country, with 125 cases now reported in 18 states, new U.S. government data shows.

That is more cases than were reported in all of 2022, the most recent annual peak for measles infections, the U.S. Centers of Disease Control and Prevention reported Friday.

So far this year, there have been seven outbreaks, with 69% of cases outbreak-associated, the CDC reported. For comparison, four outbreaks were reported during 2023, with 48% of cases outbreak-related.

Still, agency officials said they do not expect measles cases this year to top 2019, which was when health officials last said they feared the United States could lose its measles elimination status. That year, outbreaks among unvaccinated communities in New York drove the annual total to a record 1,274 cases — the most seen since the 1990s.

The latest estimate predicts the United States will likely see 300 measles cases this year, which is still above most recent years.

Following a large measles outbreak in a migrant shelter in Chicago that surfaced in March, Illinois remains the state with the largest number of measles cases this year. Fortunately, that outbreak has slowed following a major vaccination push. 

Massimo Pacilli, deputy commissioner for the Chicago Department of Public Health, acknowledged CDC reports of higher rates of vaccinated people catching measles during the outbreak, which he attributed to the intense spread of the virus within the densely packed shelter.

“In this setting, we’re observing continuing protracted exposures. And so it is not completely unexpected to see a higher proportion of individuals who may have had a dose end up being infected with measles,” Pacilli told CBS News.

While infections in the shelter have declined, the city warned doctors on Friday that a growing number of cases have been reported in the region with no links to the shelter.

And last week, the CDC said that the ongoing “importations” of the virus through unvaccinated international travelers now pose a “renewed threat” to the U.S. status of having eliminated local spread of the virus, a designation it officially achieved in 2000. 

“Rapid detection of cases, prompt implementation of control measures and maintenance of high national measles vaccination coverage, including improving coverage in under-vaccinated populations, is essential to preventing measles and its complications and to maintaining U.S. elimination status,” the CDC forecasters wrote.

More information

The U.S. Centers for Disease Control and Prevention has more on the measles.

SOURCE: U.S. Centers for Disease Control and Prevention, data, April 19, 2024; CBS News

Source: HealthDay