The number of confirmed measles cases reported in an outbreak in West Texas is now at 124, the Texas Department of Health Services said in an update Tuesday, an increase of 34 since late last week.

A measles outbreak in northwest Texas grew to 124 cases in nine counties on Tuesday, and health officials warned that residents in other parts of the state may have been exposed to the highly contagious respiratory illness.

The measles outbreak in west Texas grew to 124 cases over the weekend, with 18 patients requiring hospitalization, the state’s health department said on Tuesday. The cases increased by 34 since