The health department says it has evidence that the patient of a Tulsa oral surgeon got hepatitis C from his office.
Dr. W. Scott Harrington's offices in Tulsa and Owasso have been shut down since March.
The state health department says this is the first recorded case of patient-to-patient transmission of hepatitis C in a dentist's office.
The public hasn't heard from Harrington since he voluntarily gave up his license in March. That came after the state health department and the dental board began investigating his office, saying his practices were "unsafe and unsanitary."
Investigators from the state dental board said as many as 7,000 people may have been exposed to HIV, as well as hepatitis B and C. Thus, began several weeks of screenings for Harrington's patients by state health officials.
In total, the health department says 4,202 tests were processed by the Oklahoma Public Health Laboratory. Of those, 89 patients tested positive for hepatitis C, five for hepatitis B, and four for HIV.
Among the former dental patients who were screened and newly identified as having hepatitis C, 56 percent were over the age of 50.
Officials say local, state and federal governments have spent more than $710,000 on the public health response to this investigation.
Colby Pierce is one of Harrington's former patients. He said his test results came back negative.
"It makes me more conscious about who I go to, about who I trust," he said.
Wednesday, the health department announced that genetic tests done by the CDC indicate one of Harrington's patients transmitted hepatitis C to another patient.
"We don't know if it was due to a lapse in infection control practices or if it was due to a lack of safe injection practices," said Kaitlin Snider, of the Tulsa Health Department.
Snider said "patient A" had previously tested positive for hepatitis C, while "patient B" had not, until after visiting Harrington's office.
"We know that these two patients were seen around the same timeframe in Harrington's practice," Snider said.
Health officials said it's likely some of the screening results would be positive for infection, not related to Harrington's practice.
Harrington is accused of multiple sterilization and cross-contamination violations. Investigators said Harrington didn't keep a proper drug log, didn't have a DEA permit for his Owasso location, and used the same vials for multiple drugs. He was also accused of allowing his dental assistants to do IV sedation, which the state says is unacceptable and illegal.
Harrington is currently fighting to get his license back. A hearing is scheduled for January to decide that matter. His attorney told us Tuesday, he wants to continue to help patients.
"He misses the practice, he loves the practice, and he hopes one day to be back in the practice," said attorney James Secrest, II.
Pierce said Harrington should not be allowed to see any more patients.
"He should not get his license back. When you make that big of an error, it's not just a minor problem, it's just a really big thing and he shouldn't really get it back," Pierce said.
The health department said they have no reason to believe anyone contracted hepatitis B at Harrington's office and the results for the HIV tests won't be ready for a few weeks.
Messages left with Harrington's attorney Wednesday were not returned.