The largest hospital move in Canada's history came with an added benefit: a dramatic reduction in hospital-related infections.

When the Royal Victoria Hospital moved from its location on the slopes of Montreal's Mount Royal to the Glen Yards site, it gave researchers the opportunity to determine exactly how much the environment contributed to disease.

In this case, it came about because of the dramatic change in hospital wards, going from three or four people in a room to a 21st-Century building.

In particular, patients at the Royal Victoria were no longer sharing toilets, since each of the 500 rooms at the McGill University Health Centre is designed for one person, with a private bathroom.

The result, according to Dr. Todd Campbell Lee, was a stunning drop in rates of the superbug known as VRE: vancomycin-resistant Enterococcus.

Researchers expected to see a gradual drop in the rate of infection, but the turnaround was almost overnight.

"It really allowed us to show the benefit of going from one environment to the other right away," said Dr. Lee.

In 2013, 766 patients at the Royal Vic tested positive for VRE, and 55 had serious infections.

In 2018, just 209 patients at the Royal Vic's new building had been in contact with VRE, and only 14 had infections.

"If you get a serious infection there's a high attributable risk of death," said Dr. Lee.

While the move dramatically reduced the number of VRE infections, and the rate of infection for other superbugs was not so steep.

The number of C. difficile infections went down by about 30 percent, but that appears to be in line with a nationwide trend.

At the same time the number of people with hospital-acquired MRSA infections (methicillin-resistant Staphylococcus aureus) did not change, although the number of people who came into contact with the bacteria did drop.

While private rooms are more expensive than shared rooms, the reduction in costs in dealing with difficult to treat bacteria seems to be worthwhile.

Dr. Lee said that more research should be done to examine the economic impact of the cost of superbug infections.