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.

A child’s death this past week in Texas is the first U.S. death from measles, a highly contagious but preventable respiratory disease since 2015, according to the U.S. Centers for Disease

A recent incident in Mexia, initially suspected to be a measles case and later thought to be rubella, turned out to be a false alarm but has raised concerns about both viruses and its potential spread.