Nearly 450 patients at Massachusetts hospital may have been exposed to HIV, hepatitis

Hundreds of patients at Salem Hospital in Massachusetts were possibly exposed to hepatitis B, hepatitis C and HIV, the hospital announced.

Nearly 450 patients undergoing endoscopy at the hospital -- located 20 miles northeast of Boston -- may have been exposed over a period of two years, according to a statement from Salem Hospital released Wednesday and provided to ABC News.

Endoscopy procedures occur when a doctor inserts a tube-like instrument into the body to look inside. Types of endoscopy procedures include those such as bronchoscopies, colonoscopies and laparoscopies.

Salem Hospital said patients may have been exposed during the administration of IV medications "in a manner not consistent with our best practice."

The hospital said it was made aware of the incidents earlier this year and that it corrected the practice and notified its quality and infection control teams.

No specifics were given by hospital officials on how the exposure may have occurred or how it was corrected.

Salem Hospital said it's been working with the Massachusetts Department of Public Health since learning of the exposure and after a review, "we have determined that the infection risk to patients from this event is extremely small," the statement read.

"Salem Hospital has notified all potentially impacted patients, set up a clinician-staffed hotline to answer questions, and we are providing them with free screening and any necessary support," the statement continued. "There is no evidence to date of any infections resulting from this incident."

The Massachusetts Department of Public Health told ABC News it performed an onsite investigation at the hospital and worked with the infection control team to manage the situation.

"DPH advised the hospital to notify all impacted patients in writing about the potential exposure to bloodborne pathogens and to offer free-of-charge follow-up care, including testing," the department said.

A spokesperson for Mass Brigham – which owns Salem Hospital -- told ABC News that the tests for hepatitis B, hepatitis C and HIV are standard tests for an exposure of this kind.

The spokesperson also emphasized that that there is a small risk of infection and if patients have not been notified, they don't need to be concerned.

"The safety of our patients is our highest priority, and we have undertaken multiple corrective actions in response to this event," the statement from Mass Brigham continued. "We sincerely apologize to those who have been impacted, and we remain committed to delivering high-quality, compassionate health care to our community."

While there is a vaccine available for hepatitis B, there are no vaccines that prevent infection with hepatitis C and HIV.

Hepatitis B and C are both treatable with antiviral mediations, with the latter being 95% curable, according to the Centers for Disease Control and Prevention.

HIV is not curable but can be treated and managed with antiretroviral therapy. The medication reduces the viral load in a patient's body making the virus virtually undetectable and, therefore, untransmissible.