Measles cases reported in the United States
At least seven people in three states - Pennsylvania, Michigan and Texas - have contracted a strain of the measles that had been brought to the U.S. by a 12-year-old Japanese boy. People born before 1957 are generally immune to the measles as a result of having lived through serious measles endemics before the advent of a vaccine, according to the CDC. After 1957, effective vaccination techniques have all but eliminated U.S. strains of the virus.
But because the measles virus is highly contagious, the Centers for Disease Control and Prevention warns that cases can still occur in properly vaccinated people and those born before 1957. The CDC says healthcare providers "should consider measles in any person with clinically compatible illness."