Jan 7, 2008

Airborne Germs and Handwringing

Posted in Science at 1:00 pm by David Bradley

Just before the Christmas break, right as my annual winter festival cold kicked in and I was up to my neck in end of year deadlines, I posted a link to a press release in my Geeky Bits science extra column. That page is a repository of the less worthy, but hopefully interesting stuff I come across. Occasionally, I see an intriguing headline, give it a click, give the text a quick read through, add the item to the Bits, and thinking nothing more of it, just as one might with a del.icio.us or StumbleUpon post.

However, one regular Sciencebase reader, Churchill Fellow Grace Filby, was somewhat taken aback by my highlighting a timely press release from the London School of Hygiene and Tropical Medicine (University of London) – and described it as “a load of misguided nonsense”. Unfortunately, there is no online feedback or comments form on that LSHTM press release through which we could open a public debate on its content.

The press release was entitled – “If you don’t want to fall ill this Christmas, then share a festive kiss but don’t shake hands” – not the snappiest of titles but almost certainly one attempting to catch the wave of festive spirit seeing as it was released on December 19. However, both the title and the subheading of the press release (“The fight against all types of infections, from colds and flu to stomach bugs and MRSA, begins at home, with good hand hygiene, says first review of hand hygiene in the community.”) perhaps places too much emphasis on hand hygiene as opposed to the problem of airborne pathogens, believes Filby.

First off, Filby says that the press release “deflects the public’s attention away from a major source of germs which is the air we breathe…handwashing is only a part of it.” She adds that, “It is the germs arriving in the air that need disinfecting or freshening before the germs land on surfaces that could be touched by hands and passed to other people.” Even the British government appears to be acknowledging this to some degree, according to The Times on Christmas Eve in a bulleted item on how air disinfection
units
can kill
MRSA, and C difficileair disinfection units can kill MRSA, and C difficile.

The press release states: “But a report just published warns that we may be far more at risk of passing on an infection by shaking someone’s hand than in sharing a kiss.” As far as we can see, the full text of the original 38-page report cited in the release the word kiss or kissing occurs only once. It’s almost as if the press office hoped to catch media attention with the mistletoe and seasonal kissing theme regardless of the science reported in the report itself. Moreover, there is nothing much about handshakes or shaking hands either.

There are several other dubious details about handwashing: “but we believe that this targeted approach to home hygiene…” Is “believe” valid in a heavyweight scientific document of this sort, asks Filby.

The press release concludes that, “Handwashing with soap is probably the single most important thing you can do to protect yourselves and your loved ones from infection this Christmas.” Probably – that’s good, but we also need to deal with airborne germs. Whatever would Florence Nightingale have said? There are plenty of other risk factors out there and ways to reduce the chances of succumbing to winter bugs, such as walks in the fresh air, healthy eating, and more contentiously vitamin C or zinc supplements, although the jury is still out on the benefits of those.

Regardless, the main problem is that the press release ignores the primary source of respiratory infection which occurs from carrier to the next victim before pathogens ever fall onto a surface. In the case of many winter bugs, they spread quickly through sneezes or coughs when people don’t cover their noses and mouths.

Of course, Filby and I could put on our cynical hats at this point and come up with some kind of plausible explanation as to why hand hygiene as opposed to air hygiene is considered important. “Perhaps it is worth noting that funding for research on air hygiene wasn’t forthcoming whereas for hand hygiene there are plenty of interested parties – soap manufacturers, handwash products and water companies,” says Filby.

Hand hygiene is obviously part of the story and in the pre-Xmas rush for headlines one could forgive the LSHTM for highlighting it, but a broader perspective on all-round hygiene education and the promotion of other aspects of hygiene, as opposed to simple hand-wringing in the washroom, would have made more sense.