LAS VEGAS (AP) -- Health officials in Las Vegas say 77 more people who were treated at an outpatient clinic have been diagnosed with hepatitis C.

Authorities can't say for sure how the 77 people were infected. Officials say they know each was treated from March of 2004 to January 11th of this year.

The reports bring the number of cases linked to clinics run by the same group of doctors to 85.

In the eight cases identified earlier, seven were linked to the Endoscopy Center of Southern Nevada. The other case was traced to a sister clinic.

Authorities have said at least 50,000 patients may have been exposed to unsafe practices by clinic staff who reused syringes and single-use vials of medication during anesthesia.