Sep 18, 2013 02:42 PM EDT By Russell Westerholm, UniversityHerald Reporter

According to Oklahoma health officials, a local dentist and his practice, since shut down, were responsible for the first ever patient-to-patient transmission of hepatitis C in a dentist's office in the U.S., the Associated Press reported.

Dr. W. Scott Harrington reportedly operated with rusty equipment and his employees also reused needles. The entire practice was shut down in March after an investigation found unsanitary conditions.

Dr. Kristy Bradley said the investigation did not specify how the hepatitis was transferred, but she speculated it was likely the unsanitary equipment and malpractice of reusing needles.

"This is the first documented report of patient-to-patient transmission of hepatitis C virus associated with a dental setting in the United States," she said. "When this initially began, we didn't necessarily think we would find enough evidence of transmission, but there were enough red flags for us to (investigate)."

According to the Center for Disease Control and Prevention (CDC), Harrington's dental office spread an infectious disease. The CDC is also continuing its genetic testing of HIV specimen.

"While our investigation documents the transmission of hepatitis C, we have no reason to believe the hepatitis B cases resulted from exposure in this dental practice," Bradley said.

The state filed a 17-count complaint following the investigation that shut down Harrington's practice, calling him "a menace to the public health."

Oklahoma health officials encouraged 7,000 of Harrington's patients to submit to testing. Of the 4,202 who did so, 89 tested for hepatitis C, five for hepatitis B and four for the virus that causes AIDS.

"It's been a hard road, but the bottom line is that the state health department and Dr. Bradley saved people's lives," Oklahoma Board of Dentistry Executive Director Susan Rogers said.

Harrington is now headed down a road sure to be plagued with legal proceedings and punishment. He already surrendered his license in March and will face a hearing before the state's dental board in January. Seven of his former patients joined to file a class-action lawsuit against Harrington, his corporation, is medical staff and several pharmaceutical companies.

Five of the plaintiffs said they contracted infectious diseases as a direct result of Harrington's and others' actions.

The investigation began when a patient of Harrington's tested positive for HIV in a third-party provider's screening. James Secrest II, Harrington's attorney, has not commented by said early on that his client's record with the state was "impeccable."

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