AAAS meeting told to take a leaf out of Florence Nightingale book and allow in air, and microbes, to control nasty pathogens

Hospitals might thwart the spread of dangerous infections by taking a tip from Florence Nightingale and throwing open their windows. But while the Victorian nurse championed fresh air and cleanliness as a defence against infections, the incoming air might help control nasty pathogens by letting more microbes inside.

Jack Gilbert, a microbiologist at the US government's Argonne National Laboratory in Illinois, offers the unconventional view that unwanted microbes might gain a foothold in hospitals because they had too little competition from other organisms.

The idea mirrors that seen in the gut, where antibiotics can kill off the balanced and healthy community of bacteria, only to make way for hardier bugs that cause illness.

"When surgery first started 300 years ago, you would have people walking around with blood and pus all over their outfits. In that situation it makes a lot of sense to make the system very clean," Gilbert said at the annual meeting of the American Association for the Advancement of Science in Vancouver.

"But if you go into any wound infection clinic and speak to a surgeon, they are constantly sterilising the bejeebers out of their operating room. There is theoretically nothing there – they have scrubbed themselves with sterilising agents – but somehow, magically a pathogen gets into the person when they're in the operating theatre and they get sick.

"This is a situation where one organism from one person hasn't had any competition from any other microbes on the skin or in the environment because there's nothing else there," he said.

Nightingale noted the virtues of open windows in her Notes on Nursing in 1859. "True nursing ignores infection, except to prevent it. Cleanliness, fresh air from open windows, are the only defence a true nurse either asks or needs," she wrote.

Last month, Jessica Green at Oregon University reported that air conditioned hospital rooms had less diverse populations of microbes compared with rooms that were aired by leaving the windows open. But the air conditioned rooms had a greater portion of pathogens that lived on humans or belonged to groups that caused disease.

In a 2009 study, Andreas Voss at the Canisius-Wilhelmina hospital in the Netherlands, found that fewer than half of hospital staff washed their hands after using the toilet. He speculated that they might be more lax about their personal hygiene because the hospital environment was so clean.

"There's a good bacterial community living in hospitals and if you try to wipe out that good bacterial community with sterilisation agents and excessive antiobiotic use, you actually lay waste to this green field of protective layer, and then these bad bacteria can just jump in and start causing hospital borne infections or mediated infections," Gilbert said.

"If you open the windows and let all of these other bacteria in from outside, you will either dilute out the pathogens or not allow the pathogens to establish themselves because there is too much competition for the nutrients and energy that the bacteria need to survive," he added.

Mark Enright, research director at AmpliPhi Biosciences and a microbiologist at Bath University, said: "I do think that opening windows is a good thing. Air flow is a good thing in hospitals; you don't want pockets where organisms can pool and swarm and pass on."

But he described the idea that hospitals were too clean as "quite an extreme view".

"Given the opportunity, any bacterium that gets into the bloodstream and into sterile tissue will in invade and cause problems and produce toxins that can kill," he said.