LAS VEGAS — The Southern Nevada Health District says it has identified another 77 people who may have been infected with hepatitis C during medical treatment at a Las Vegas outpatient clinic.

That’s in addition to seven acute hepatitis C cases already associated with the outbreak traced to the Endoscopy Center of Southern Nevada.

The 77 are among about 400 people a health district official says tested positive for hepatitis since the outbreak was made public Feb. 27. Each has been matched with patient lists and interviewed.

The official says these patients had no other identifiable risk factors other than their treatment at the clinic between March 2004 and Jan. 11.

The Las Vegas-based health district says about 50,000 hepatitis virus tests have been performed at local labs. But the district says it can’t be sure whether everyone who’s been asked to get tested has done so.