The Texas Department of State Health Services reported Tuesday its measles cases, which date back to late January, had grown to 663 cases as of Tuesday, marking a jump of 17 cases since the state’s last update as 87 of the patients have been hospitalized while two school-aged children have been confirmed dead from the illness.

Since the measles outbreak began in West Texas, 87 people in Texas have been hospitalized, and two school-aged children have died.

As more counties are being impacted by the ongoing measles outbreak and added to the growing list of counties across Texas, here's what to know.