Would filtering farts prevent hospital acquired infections?

Chris - This is a question that we answered a few years ago and Ben Valsler went to see Simon Park, in Surrey, who actually did the experiment for us and we've got the bit of audio from 4 years ago in 2008 where they did the experiment to see how efficiently farts can spread potential pathogens.

Ben - We know that coughs and sneezes can spread diseases and that's how many respiratory infections actually get transferred, but you were thinking there might be another way that bacteria could be transmitted.

Simon - Yes. I have two sons, Joe and Josh and they've developed a sort of obsession with this homemade biological prank of farting and I thought, why do we find this so offensive and why is it dangerous, and can I demonstrate this to my children to stop them doing it?

So I thought of some experiments where I could actually prove whether or not farts could transmit bacteria. So, what I've done is taken some agar plates that are very good at culturing faecal bacteria and done some very crude experiments where we've exposed the plates to people farting in terms of a naked fart with no pants and no jeans on, and also, people farting with underpants and jeans on.

Ben - So you've set this up by passing wind shall we say, on what's called a MacConkeys agar plate. One of them clearly has some colonies on and the other one looks completely clean. So, Simon, which one is which?

Simon - The plate that's totally clean is one that was exposed with pants and jeans on, so it's obviously the pants and jeans are being very effective at filtering out any faecal bacteria, but the plate that was exposed to the naked emission has a splattering of red colonies on it and they are very indicative of E. coli that's a very common faecal bacteria. That's a good indicator of faecal contamination. There's such huge numbers of bacteria in a stool that it's inevitable that we will transmit bacteria after flatulence.

Chris - So the bottom line is - if you excuse that pun - if you cover the area, as someone hopefully in hospital staff and patients would be expected to be, then the infectious transmission risk is probably extremely low. If you go around flatulating on people in hospital without the rear uncovered, there is a likelihood you may expel some organisms that could make people unwell.