OKLAHOMA CITY ? Health officials treating hepatitis C cases tied to a Norman nurse anesthetist may have to test more than twice as many patients for the disease than they first thought.

Up to 720 former patients of a Norman clinic and two Oklahoma City clinics may have been exposed.

Earlier, testing was limited to 350 patients from the Norman clinic. Since then, officials have said anesthetist James C. Hill also practiced at Northwest Surgical Hospital and Oklahoma Center for Orthopedic and Multi-Specialty Surgery.

As of Friday, 52 people had tested positive for hepatitis C exposure after receiving treatment from the Norman Regional Hospital pain management clinic.

State epidemiologist Dr. Mike Crutcher said 730 people have been contacted. Crutcher said Hill has admitted routinely reusing needles for injections on up to 25 people per day.

Several lawsuits have been filed naming Hill and anesthesiologist Dr. Jerry W. Lewis, for whom Hill sometimes worked as an assistant. Crutcher said the state Health Department has stopped investigating Lewis and that there is no evidence to suggest Lewis put any patients at risk.