The number of people with measles in Texas increased to 146 in an outbreak that led this week to the death of an unvaccinated school-aged child, health officials said Friday. The number of cases — Texas’ largest in nearly 30 years — increased by 22 since Tuesday.

The number of confirmed measles cases in western Texas grew to 146, and it is possibly spreading to the central part of the state and neighboring New Mexico, health officials said Friday.

Vaccine hesitancy has been rising for years in the United States. Doctors and parents in one rural county are confronting the consequences.