Measles infections have surpassed 100 cases in the United States, nearly doubling the number reported in 2023

The spread of measles infections persists in various parts of the United States, with the latest nationwide tally surpassing 100 cases.

As of April 5, the Centers for Disease Control and Prevention (CDC) reported a total of 113 cases across 17 states, nearly doubling the count of 58 cases recorded for the entirety of 2023.

Seven outbreaks, defined by the CDC as three or more related cases, have occurred so far this year, up from four in 2023. Over 70% of cases are associated with outbreaks, and around half of the patients are children under five years old.

More than 80% of measles infections are among the unvaccinated or those with an unknown vaccination status, while 12% are individuals who have received only one dose of the measles, mumps, and rubella (MMR) vaccine.

Chicago has borne the brunt of the U.S. cases, with 58 infections reported as of April 8, primarily linked to an outbreak at one of the city’s largest migrant shelters.

However, in an encouraging update from the Chicago Department of Public Health (CDPH) on April 5, measles cases in the city were on the decline, with only five new cases reported during the week of March 31 through April 5, compared to 23 infections reported the previous week.

CDPH has been proactive in responding to measles reports, conducting over 75 MMR vaccine events at the city’s new arrival shelters since March, resulting in over 6,000 migrants getting vaccinated.

Other notable measles hotspots include Florida, where 11 cases have occurred this year, primarily among students at an elementary school in Broward County. State health officials declared the end of the infection period tied to the school cases on March 8.

Concerns over measles outbreaks in the U.S. intensified in January, particularly in Philadelphia, where reports indicated nine people were infected in an outbreak involving a children’s hospital and daycare center.

Measles, a highly contagious disease, can lead to severe complications such as pneumonia and encephalitis, and may result in death for 1 to 3 children per 1,000 infected individuals.

Amid the rise in measles cases, the CDC issued an advisory on March 18 urging parents to ensure their children receive two doses of the MMR vaccine, which is 97% effective.

The surge in cases coincides with a decline in vaccination rates and an increase in exemptions among kindergartners for the 2022-2023 school year. Public health experts remain vigilant about potential outbreaks, particularly in communities with low vaccination rates, where clusters of vulnerable populations may be at risk.