- March 18, 2025
Expanding Measles Outbreak in the United States
The Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory to notify clinicians, public health officials, and potential travelers about a measles outbreak in Texas and New Mexico and offer guidance for prevention and monitoring. As of March 7, 2025, Texas and New Mexico have reported 208 confirmed cases associated with this outbreak (198 in Texas and 10 in New Mexico). As a part of this outbreak, two deaths have been reported: one in Texas and one in New Mexico. More cases are expected as this outbreak continues to expand rapidly. As of March 14, 2025, there are no reported cases in Cameron County.
With spring and summer travel season approaching in the United States, CDC emphasizes the important role that clinicians and public health officials play in preventing the spread of measles. They should be vigilant for cases of febrile rash illness that meet the measles case definition and share effective measles prevention strategies, including vaccination guidance for international travelers. See the link below to the HAN for additional information:
Contact Cameron County Public Health at 956-247-3625 if you have any questions.
Summary
The risk for widespread measles in the United States remains low due to robust U.S. immunization and surveillance programs and outbreak response capacity supported by federal, state, tribal, local, and territorial health partners. Measles-mumps-rubella (MMR) vaccination remains the most important tool for preventing measles. To prevent measles infection and spread from imported cases, all U.S. residents should be up to date on their MMR vaccinations, especially before traveling internationally, regardless of the destination.
Background
As of March 6, 2025, a total of 222 measles cases have been reported by twelve U.S. jurisdictions this year: Alaska, California, Florida, Georgia, Kentucky, New Jersey, New Mexico, New York City, Pennsylvania, Rhode Island, Texas, and Washington; 201 of which occurred in New Mexico and Texas. Most of the 222 cases are among children who had not received the MMR vaccine. There have been three outbreaks, with an outbreak defined as three or more related cases, reported in 2025, and 93% of cases are outbreak-associated. For comparison, 16 outbreaks were reported during 2024 and 69% of cases were outbreak-associated.
Measles is a highly contagious viral illness that typically begins with fever, cough, coryza (runny nose), and conjunctivitis (pink eye), lasting 2-4 days prior to rash onset. Measles can cause severe health complications, including pneumonia, encephalitis (inflammation of the brain), and death. The virus is transmitted by direct contact with infectious droplets or by airborne spread when an infected person breathes, coughs, or sneezes. Measles virus can remain infectious in the air and on surfaces for up to 2 hours after an infected person leaves an area.
Infected people are contagious from 4 days before the rash starts through 4 days afterward. The incubation period for measles, from exposure to fever, is usually about 7–10 days, and from exposure to rash onset is usually about 10–14 days (with a range of 7 to 21 days).