State health officials identified 36 new measles cases since Tuesday. The first cases were reported in El Paso County on Friday. State health officials on Friday said the number of measles cases in the state linked to a West Texas outbreak has grown to 541 since January. The Texas Department of State Health Services reported 36 new cases on Friday.

Texas’ measles case count jumped again, new data showed on Friday, with an additional 36 cases reported in the prior three days. The state has now reported a total of 541 measles cases in the ongoing outbreak that began in West Texas in January,

State health officials added four more counties to what they consider “outbreak areas” and advise those visiting or living in those counties to consult measles vaccination guidance for those areas.