Increase in Global and Domestic Measles Cases and Outbreaks: Ensure Children in the United States and Those Traveling Internationally 6 Months and Older are Current on MMR Vaccination

Summary
The Centers for Disease Control and Prevention (CDC) is issuing a Health Alert Network (HAN) Health Advisory to inform clinicians and public health officials of an increase in global and U.S. measles cases and to provide guidance on measles prevention for all international travelers aged ≥6 months and all children aged ≥12 months who do not plan to travel internationally. Measles (rubeola) is highly contagious; one person infected with measles can infect 9 out of 10 unvaccinated individuals with whom they come in close contact. From January 1 to March 14, 2024, CDC has been notified of 58 confirmed U.S. cases of measles across 17 jurisdictions, including seven outbreaks in seven jurisdictions compared to 58 total cases and four outbreaks reported the entire year in 2023. Among the 58 cases reported in 2024, 54 (93%) were linked to international travel. Most cases reported in 2024 have been among children aged 12 months and older who had not received measles-mumps-rubella (MMR) vaccine. Many countries, including travel destinations such as Austria, the Philippines, Romania, and the United Kingdom, are experiencing measles outbreaks. To prevent measles infection and reduce the risk of community transmission from importation, all U.S. residents traveling internationally, regardless of destination, should be current on their MMR vaccinations. Healthcare providers should ensure children are current on routine immunizations, including MMR. Given currently high population immunity against measles in most U.S. communities, the risk of widescale spread is low. However, pockets of low coverage leave some communities at higher risk for outbreaks.