Measles has sickened nearly 150 mostly unvaccinated people in rural West Texas, and a school-age child has died.

The number of measles cases associated with an outbreak in Texas has increased to 159 -- an increase of 13 cases in the past five days, authorities said on Tuesday.

Texas is experiencing its largest measles outbreak in 30 years, primarily affecting the South Plains region. A child has died and several people have been hospitalized by the extremely contagious disease that was once considered eradicated,