Measles Outbreak Map Reveals Where Cases Are Spiking

Cases of measles have been recorded in at least 18 U.S. jurisdictions since the start of the year, as health officials battle to contain further spread of the disease.

As of April 11, the Centers for Disease Control and Prevention (CDC) has recorded a total of 121 measles cases across the U.S. in Arizona, California, Florida, Georgia, Illinois, Indiana, Louisiana, Maryland, Michigan, Minnesota, New Jersey, New York City, New York State, Ohio, Pennsylvania, Virginia and Washington.

While most of these jurisdictions have only recorded a small number of cases (between one and nine), larger outbreaks have been seen in Florida (between 10 and 19) and in Illinois (50 to 99).

One of the worst-affected areas this year has been Chicago, where 61 cases have been recorded so far, with 54 percent of these cases in those aged under four years, according to the Chicago Department of Public Health.

Since the Chicago outbreak was detected in early March, the average number of daily measles vaccines administered has increased sharply from an average of below 200 to a peak of 725 in late March and a consistent average well above 300.

A cluster of cases was also recorded in Florida, with seven cases detected among students at Manatee Bay Elementary in Weston in February.

A CDC report published last week revealed that the number of cases reported in the first quarter of 2024 represented a 17-fold increase on the mean number of cases reported during the same period from 2020 to 2023.

The report added that the "rapid increase in the number of reported measles cases during the first quarter of 2024 represents a renewed threat to elimination."

The disease was officially eliminated in the U.S. in 2000, meaning that it is no longer constantly present and only appears when someone contracts the disease abroad and returns to the country.

In 2024, there have been a total of seven outbreaks across the U.S. (defined as three or more related cases), and 71 percent of cases (86 out of 121) are outbreak-associated. In comparison, there were only four outbreaks in 2023, and 48 percent of cases were outbreak-associated.

The worst-affected age-group is those aged under five, representing 47 percent of cases. In comparison, the 5-19 years age group represents 22 percent of cases and the 20 years-plus age group represents 31 percent of cases.

The CDC also noted that 82 percent of cases have been detected in the unvaccinated or those whose vaccination status was unknown. It also warned that the vaccination coverage among U.S. children in kindergarten has decreased from 95.2 percent during the 2019-2020 school year to 93.1 percent in 2022-2023, leaving around 250,000 children at risk.

Measles is a contagious respiratory infection that causes a rash and fever, and can lead to pneumonia and other complications. Symptoms include high fever, rash, cough, runny nose and red eyes.

It spreads through the air via coughs or sneezes. A non-immune individual can contract the infection up to two hours after an infected person was in the same room. Infected individuals can also spread measles four days before a rash ever appears, and four days after it does appear.

The CDC told Newsweek that while importations of measles cases into the U.S. are expected to continue, the risk from measles "for the majority of the population would still remain low... because most people in the U.S. are vaccinated."

It added: "If measles re-establishes itself by having ongoing circulation, the U.S. will lose its elimination status. CDC defines measles elimination as the absence of continuous disease transmission for 12 months or more in a specific geographic area.

"Even though we still have measles cases in the U.S., the majority of cases can be linked back to travelers who become infected with measles in other countries."