An outbreak of hepatitis C at the Endoscopy Center of Southern Nevada may represent "the tip of an iceberg" of safety problems at clinics around the country, according to the head of the Centers for Disease Control and Prevention. Nevada health officials are trying to contact about 40,000 patients who received anesthesia by injection at the clinic between March 2004 and Jan. 11 to urge them to get tested. Healthcare accreditors "would consider this a patient safety error that falls into the category of a 'never event,' meaning this should never happen in contemporary healthcare organizations," said CDC head Julie Gerberding.