The Texas health department reported 561 cases of measles in the state on Tuesday, an increase of 20 from April 11, as the United States battles an outbreak of the childhood disease that began in the West Texas area.

State health officials said fewer than 30 of the cases identified by the state were considered "actively infectious."

Texas health officials reported 36 new measles cases Friday, bringing the total number of confirmed cases since late January to 597. The state’s public health department estimates that fewer than 30 of the confirmed cases — about 4% — are “actively infectious.