Texas health officials reported 663 measles cases in the state on Tuesday, accounting for the majority of cases across the U.S., which reached nearly 900 as of Friday, according to the Centers for Disease Control and Prevention.

Texas health officials reported 17 new measles cases on Tuesday, bringing the total confirmed cases since late January to 663. The state’s public health department estimates that fewer than 10 of the confirmed cases — about 1% — are “actively infectious.

The measles outbreak centered in the South Plains region of Texas grew to 663 cases on Tuesday, according to health officials. The latest update from the Texas Department of State Health Services adds 17 new cases since the agency's last update on Friday.