ST. CLOUD - The Minnesota Department of Health has released their final report on last year's outbreak of blood infections, caused by a St. Cloud Hospital employee diverting narcotics for their own use.

On February 12, 2011, the Health Department was alerted to the rash of mysterious bacterial infections affecting post-surgical patients at St. Cloud Hospital.

MDH epidemiologists soon determined all 25 patients had been in the same ward, and had all been given intravenous narcotic pain medication.

After an investigation, experts determined the bacteria was accidentally introduced into patients' IV bags while a hospital employee diverted the narcotics for personal use.

On March 8th, 42-year-old hospital nurse Blake Zenner of Kimball admitted he accessed lock boxes during work and used syringes to remove the drug Dilaudid from the IV bags.

In certain instances, Zenner injected saline into the bags to replace the missing drug.

Of the 25 patients infected, 6 were placed in intensive care, three needed emergency surgery, and one died two days after being infected.

Zenner pleaded guilty last week, and faces up to four years in federal prison.

The Health Department says, this shows how serious drug diversion by hospital employees can be, and stresses hospitals remain watchful for staff drug abuse.