FAYETTEVILLE, N.C. — A division of the North Carolina Department of Health and Human Services will investigate after about 160 patients at Cape Fear Valley Medical Center may have been exposed to staph infection from improperly sterilized surgical instruments.

A hospital technician noticed on Monday that the surgical instruments had not been sterilized with steam.

The affected patients were quickly notified, and no infections have been reported. Officials said the chances of a related infection are low.

"We're conducting a root cause analysis right now to determine exactly what happened," said Clinton Weaver, a hopsital spokesman.

"We need to go through that process and see if it was a process issue or a human error issue."

The hospital says the instruments were cleaned, disinfected and packaged but hadn't been sterilized with steam before they were used on patients last weekend.

Chief medical officer Dr. Eugene Wright said the instruments were believed free of blood-borne diseases like HIV and hepatitis B and C.

He also noted that surgical patients are routinely given antibiotics to ward off infection.

Dr. Chuck Chima, physician adviser to infection control at the hospital, said steam sterilization is the third step of the disinfection process and without it, instruments could be contaminated with bacteria from the hands of employees.

"Most of the (cleaning) process had gone through," Chima said. "The (steam sterilization) is sort of an insurance."

Symptoms of staph infection include redness, swelling, pain and warmth at the surgical site as well as fever and drainage from the surgical area, swollen glands and a red streak from the infection site.

Chima said bacteria could cause regular staph infections, but not Methicillin-Resistant Staphylococcus Aureus, or MRSA, a potentially fatal infection.

Wright said the hospital discovered the problem Oct. 6 when a technician noticed that an instrument package hadn't been steamed. Packages have chemical indicators that show whether they have been exposed to steam.

Officials are investigating the problem, Wright said.

The hospital also has added steps to the sterilization process to make sure all instruments are steamed, he said.