The Centers for Disease Control and Prevention (CDC) has issued an alert to public health officials warning that the number of U.S. measles cases this year has already matched the entirety of 2023. Currently, 17 states have reported measle cases, including the AHPA states of California, Illinois, Florida and Ohio. Keep reading to learn more about the outbreak and how the states are responding.

More about the Outbreak

Measles was declared eliminated in the United States in 2000 following a 12-month absence of continuous transmission of the disease. However, there have been notable epidemics over the past 24 years – notably in 2019, when over 1200 cases were reported. Research has found failing vaccination rates, as well as increased travel and immigration, as contributing factors.

  • 2023 data shows that approximately 92% of U.S. children have received the MMR vaccine by age 2 – below the federal target of 95%.
  • International travel by unvaccinated people increases the chance of acquiring measles abroad and bringing it back to the U.S.
  • Growing numbers of undocumented immigrants with measles or no vaccination against the disease are also increasing the likelihood of the disease’s proliferation.

The State-Level Response

  • Florida has seen an increase in measles cases after an outbreak at an elementary school in Weston led to nine confirmed cases in Broward County. The Florida Surgeon General issued a letter that deferred to parents on whether to send unvaccinated children to school, directly contradicting CDC guidance recommending unvaccinated children be excluded from school for 21 days after exposure.
  • California has reported one case in San Diego. The patient is an unvaccinated one-year-old who is reported to have recently traveled overseas.
  • Illinois has reported 12 cases so far in the city of Chicago, with multiple cases being reported from a migrant shelter. Officials have requested that residents of the migrant shelter and surrounding neighborhood remain in place until authorities can determine who is vaccinated and thus immune to measles. Nearly half of the residents in the shelter were identified as not being immunized against the disease.
  • Ohio reported a potential mass exposure that might have occurred at a “Disney On Ice” show in Cincinnati. The Cincinnati Health Department put out a form to help with contact tracing.