A health worker tests for measles at a mobile testing site in Texas in February. Case numbers are continuing to climb in Texas and a nearby New Mexico county.
Mandatory Credit:	Julio Cortez/AP via CNN Newsource

A health worker tests for measles at a mobile testing site in Texas in February. Case numbers are continuing to climb in Texas and a nearby New Mexico county.
Mandatory Credit: Julio Cortez/AP via CNN Newsource