DENVER (CBS4)– A sterilization breach at Porter Adventist Hospital could have impacted an unknown number of patients. The investigation centers around people who had orthopedic or spine surgery over an 18-month period and could be at risk for Hepatitis B, Hepatitis C or HIV.

The Colorado Department of Public Health and Environment is investigating what it calls a “significant health breach” at Porter Adventist Hospital in Denver.

Dr. Larry Wolk with the health department told CBS4 that the organization is working with the hospital to notify people who had orthopedic or spine surgery there between July 21, 2016 and Feb. 20, 2018.

The infection control breach may have put some orthopedic or spine surgery patients at risk for surgical site infections or for Hepatitis B, Hepatitis C or HIV.

Wolk said in a statement, “The process for cleaning surgical instruments following orthopedic and spine surgeries was found to be inadequate, which may have compromised the sterilization of the instruments.”

When CBS4’s Jamie Leary asked how wide spread the health breach is, a health department spokesperson said it was “significant.” No specific numbers of patients at risk was provided. The hospital mailed letters on April 4 to patients who may have been put at risk.

The Colorado Department of Public Health and Environment was notified of the breach on Feb. 21. The department conducted an on-site survey of the infection control practices at the hospital the next day. A disease control investigation is ongoing.

Health officials with the state last visited the hospital on March 28 and determined that the current infection-control practices meet standards.

Centura Health released this statement on Wednesday afternoon, “Patient safety is our top priority at Porter Adventist Hospital. We are proactively working with the Colorado Department of Public Health & Environment about a gap in the pre-cleaning process, prior to sterilization. While we take any gap in our pre-cleaning process seriously, at this time we are not aware of it having caused any infections. We are reaching out to patients who underwent orthopedic and spine surgery during the time in question. We remain committed to transparency, additional details will be forthcoming.”

According to the health department, “Porter Adventist Hospital stopped using and reprocessed all surgical equipment in question Feb. 20. While there is always a risk of infection during surgery, it appears there is no increased risk to current patients having surgery at Porter Adventist Hospital because of the infection control breach.”

An “emergency line” has been set up for patients concerned about the sterilization issue, specifically if they believe they may have been affected: 303-778-5694.

Porter Adventist Hospital near Logan and Downing in Denver is operated by Centura Health.