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.

The measles outbreak in Texas has reached nearly 150 cases, according to a Friday morning update from the state health department. The agency said 146 cases have been identified since late January. Twenty of those patients have been hospitalized, and one school-age, unvaccinated child has died.