The rate of tuberculosis among Montgomery County residences is twice the national average and is the highest in Maryland, state data show.

The county saw 73 cases of tuberculosis in 2011, for a “case rate” of 7.6 cases per 100,000 residents, Montgomery County Health Officer Ulder Tillman told the Montgomery County Council on Tuesday. By comparison, Maryland had 234 cases, for a rate of four cases for every 100,000 residents, while the United States had a case rate of 3.6.