Counties in California, New York and Maryland detected their first measles cases of the year. The CDC has warned travelers to be vigilant as spring break begins.

Philadelphia hospital patients were also warned about possible exposure to the highly contagious virus just days after a warning for Dulles airport travelers.

The measles outbreak in the South Plains region of Texas has been linked to confirmed cases in New Mexico and Oklahoma. The outbreak in West Texas is centered in Gaines County, which neighbors Lea County,