LAS VEGAS -- A seventh case of acute hepatitis C has been confirmed in the Southern Nevada Health District's investigation into the outbreak, but officials said this case was contracted at the Desert Shadow Endoscopy Center.

Originally diagnosed in 2006, the seventh case was never reported to the health district. Officials said that just before having a procedure done at the center that summer, the patient tested negative for hepatitis C. The patient was diagnosed with acute hepatitis C several weeks after the procedure was completed.

"Our investigation is continuing regarding this potential case," health district officer Dr. Lawrence Sands said. "We advised the commission because we believe it is important information and should be taken into consideration as the clinic’s business license is debated."

While they say they do not have enough information to know what kind of notice to send, officials recommend any former patients of the Desert Shadow Endoscopy Center should discuss the need for testing with their doctor.

The Desert Shadow facility is also owned by Dr. Dipak Desai. During the center's preliminary investigation, officials found that staff at the Endoscopy Center of Southern Nevada had reused syringes and vials, exposing 40,000 patients to hepatitis C over a four-year period.

Six cases of acute hepatitis C have been confirmed from the Endoscopy Center, but officials said the number may increase with the continual investigation.

Desai's other clinics -- including the Desert Shadow Endoscopy Center -- were prohibited from performing medical procedures while the federal and state departments continued their investigation.