March 14, 2025

U.S. CDC: Expanding Measles Outbreak in Texas and New Mexico and Guidance for the Upcoming Travel Season

Please take a moment to review this update on measles activity in the United States, information on measles prevention, and response guidance for the upcoming travel season. A large measles outbreak is ongoing in Texas and New Mexico. Smaller outbreaks have been reported in New Jersey and Georgia, and there are other cases in several additional states. No measles cases have been reported in Maine in 2025; the most recent case was in 2019. Of particular concern is the outbreak in Texas/New Mexico, where measles is circulating in a close-knit community with low vaccination coverage. Two deaths have been reported there, both in unvaccinated individuals. Federal, state, and local public health authorities are collaborating with community partners to stop this ongoing outbreak.

Measles elimination in the U.S. has been maintained since 2000, indicating no sustained local measles spread. When 95% of people in a community are vaccinated, herd immunity protects most people. Vaccination coverage for two doses of measles-mumps-rubella (MMR) vaccine in kindergarten children in the 2023-2024 school year was 92.7% nationally and 97.5% in Maine. This reduces the risk of a measles outbreak. However, this does not prevent measles introductions from outside of a community. Measles remains endemic in many other countries, and unvaccinated or under-vaccinated persons who travel internationally can become infected and transmit the disease in the U.S. Community outbreaks can still occur, particularly in areas with low vaccine coverage, and it remains crucial to continue MMR vaccination efforts to protect individuals and communities. Clinicians should be aware of Maine's child care, school, and health care immunization rules and U.S. CDCs immunization schedules.

Laboratory testing remains an important part of measles diagnosis and confirmation. Specimens should include oropharyngeal or nasopharyngeal swab for polymerase chain reaction (PCR) and serum for IgM serology. The Maine CDC prefers measles specimens for PCR testing to be submitted to the Maine Health and Environmental Testing Laboratory (HETL). This allows the Maine CDC to better track the timeline of the result. At HETL, a measles PCR result is generally available within 13 business days of specimen receipt. Measles PCR testing is also available at some commercial laboratories. Please see the HETL Laboratory Submission Information Sheet (LSIS) before submitting specimens to HETL for measles PCR testing. HETLs Measles PCR LSIS can be found at https://www.maine.gov/dhhs/mecdc/public-health-systems/health-and-environmental-testing/micro/documents/Measles-Virus-Detection-by-Real-Time-RT-PCR-Assay-LSIS.pdf Many commercial laboratories offer measles IgM testing, and HETL does not offer this testing. If specimens are submitted to HETL for serologic testing, they will be forwarded to a reference laboratory.

Advisory (PDF)