A reported "small number" of patients who underwent surgery in recent months at UPMC Northwest in Seneca, Venango County, may have been exposed to what the hospital describes as "a health risk."

In a statement released yesterday, the hospital said patients who underwent surgical procedures there face "an extremely low risk" of illness resulting from a problem the hospital declined to describe.

UPMC Northwest spokeswoman Pamela Niederriter said the release represents the only information the hospital would provide about the health risk.

But The Derrick newspaper in nearby Oil City reported yesterday that "a failure to follow equipment sterilization guidelines" at the hospital resulted in "the notification of more than 100 surgical patients who may have been exposed to viruses as varied as hepatitis and Human Immunodeficiency Virus (HIV)."

"Several reports indicate that an autoclave -- hospital equipment that sterilizes surgical and related instruments -- was heated at a level not set to ensure infection control," The Derrick reported.

The improper setting was in place from January through at least July at the hospital, it reported.

But in its own release, the hospital said it thoroughly investigated the problem before concluding that patients faced an extremely low health risk.

"However, as a precautionary measure, the hospital has notified the patients and their physicians of the potential risk and has offered to provide appropriate follow-up laboratory testing at no charge to the patients," its release said.

It also noted that the hospital "has taken appropriate steps to ensure that the situation will not occur in the future."

Stacy Kreideman, spokeswoman for the state Department of Health, said UPMC Northwest reported the problem through the Pennsylvania Statewide Reporting System, as required by law. However, the health department cannot disclose the nature of the problem due to concerns for patient confidentiality.

"We will monitor its response to the situation and make sure it followed procedures and protocols to protect patients," Ms. Kreideman said. "If we find deficiencies, then we will post the survey, or citation, on our Web site on what we found and how the problem was corrected."