CDC staff received an email this week telling them to avoid using more than a dozen terms or words-- including "health equity," "race," "bias," and "disparity" -- in their annual performance evaluations;

According to the society, the last US measles death was in 2015. A measles infection can have particularly devastating complications for pregnant women and young children, including pneumonia, neurological impairment, hearing loss and death.

The first person known to have died from measles in the U.S. in a decade was announced by health officials on Wednesday and described as a "school-aged child" who perished in a children's hospital in West Texas,