The Centers for Disease Control and Prevention (CDC) has issued a Health Alert Network (HAN) Health Advisory to notify clinicians, public health officials and potential travelers about a measles outbreak, primarily in Texas and New Mexico, and to offer guidance for prevention and monitoring.

As of March 18, more than 300 cases of measles have been recorded in the U.S. this year, according to the Centers for Disease Control and Prevention (CDC). The Texas Department of State Health Services has recorded 279 cases, with 38 more in New Mexico. One death has been confirmed, and at least 50 people have been hospitalized nationwide.

“With spring and summer travel season approaching in the United States,” the alert said, “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.”

The CDC said that the risk of a widespread measles outbreak in the U.S. remains low because of strong immunization and surveillance programs and the capacity for all levels of government to respond.

For maximum protection against measles infection and spread, the CDC urges that all U.S. residents are up to date on their measles-mumps-rubella (MMR) vaccinations, especially before traveling internationally.