By NICK TROUGAKOS The Associated Press

OKLAHOMA CITY (AP) - A hepatitis C outbreak that has infected 52 people in Oklahoma has led to a national warning to nurse anesthetists against reusing needles in intravenous tubes.

James C. Hill, a nurse anesthetist in Oklahoma City, told health officials he reused needles and syringes up to 25 times a day to inject pain medication through intravenous tubes at a pain management clinic in Norman and two surgical centers in Oklahoma City. Such reuse of needles can spread the disease, which can lead to serious liver damage, cancer and even death.

Hill is under investigation by the state Department of Health and the Oklahoma Board of Nursing.

Health officials have sent letters to 1,220 patients treated by Hill, telling them to get tested for hepatitis C, and 52 of the patients have tested positive since late August.

Last year, 19 patients of a Brooklyn, N.Y., clinic contracted hepatitis C when an anesthesiologist reused needles and a vial of medication.

The American Association of Nurse Anesthetists has sent 33,000 letters to hospital administrators, nurse anesthetists and nursing students nationwide, citing the Oklahoma outbreak and telling them not to reuse needles. Experts say some health practitioners may not be aware that reusing needles is dangerous because the needles are inserted into tubes rather than under the skin.

"After discussion with infection control experts, we have concerns there may be a widespread misunderstanding by health care practitioners of the dangers associated with the reuse of needles and syringes," the letter said.

Dr. Elliot Greene, associate professor of anesthesiology at Albany Medical College in Albany, N.Y., said studies done in the 1990s documented that health care professionals sometimes reused needles when injecting drugs into intravenous tubes.

"It was a shocking thing to see," said Greene, who serves on the task force for infection control in the American Society of Anesthesiologists. He said the problem has to do with a lack of education.

"There are a lot of people who started their practice before this was an issue," Greene said. "They got into certain practice patterns that are now considered bad technique."

Jeff Beutler, executive director of the nurse anesthetists association, said that when a shot is given into an intravenous line, a needle can easily come into contact with a patient's blood. Blood-to-blood contact spreads hepatitis C.

Beth Bell, chief of the epidemiology branch in the division of viral hepatitis at the Centers for Disease Control and Prevention, said research clearly shows the danger of reusing needles.

"The way that these kind of intravenous tubes are placed, what often occurs is that there is a back-flow of blood into the intravenous tube," she said.

State Epidemiologist Dr. Mike Crutcher said Hill believed he was practicing safe medicine.

"He didn't think it was abnormal procedure," Crutcher said. "It's hard to imagine that he would think it was normal."