December 8, 2012
Recent studies show that if you kept your fingers away from your face and out of your mouth-nose-eyes, you’d lower your risk of self-inoculating with opportunistic germs.
Cursing your sick colleague for the infection you can feel settling into your chest? You might want to aim the finger of blame closer to home. It’s entirely possible you may have infected yourself with whatever respiratory bug has latched onto your lungs. The same can be said about some of the stomach-wrenching gastrointestinal ailments people occasionally get.
People sometimes self-inoculate. They take germs they picked up on their hands when they were hanging onto bus poles and they deliver the bugs to places where those bugs can go from harmless to disease causing. They stick germ-coated fingers into their mouths, they rub their eyes, they are even known to poke a finger into a nostril.
Bug on skin becomes bug on mucus membrane – a much more porous surface and an easier route to a warm and welcoming place for the bug.
Handwashing and alcohol gels can slough those germs off your fingers. And that’s why public health officials repeat the handwashing mantra relentlessly.
But a group of researchers suggests there’s a part of the prevention equation that public health folks don’t stress often enough: If you kept your fingers out of your mouth-nose-eyes, you’d lower your risk of self-inoculating.
“People touch their faces, touch their mouths, pick their noses and all of that. And in those behaviours they can bring these viruses that are on their hands to the muscosa … where they can really infect us,” says Wladimir Alonso, an infectious diseases researcher at the U.S. National Institutes of Health’s Fogarty International Center.
Alonso and some colleagues wrote a letter to the Journal of Infectious Diseases recently to make the point. They had done a small study where they observed 249 randomly selected individuals in public spaces in Florianopolis, Brazil and on the Washington, D.C. subway system. The individuals they observed touched common surfaces and their mouth and nose area at a rate of 3.3 and 3.6 touches respectively an hour.
Their point? Handwashing alone can’t keep up with the infection potential of self-inoculation events. Or as they put it, ” … the opportunities for hand re-contamination in public settings occurs at a much higher rate than any viable hand washing frequency.”
They suggest public health campaigns should also teach people about how they infect themselves by touching their mucus membranes, so they become more aware of the role these behaviours could play in acquiring infection.
Dr. Jody Lanard likes the suggestion. A risk communications expert based in Princeton, N.J., Lanard monitors public health messaging about influenza closely, and says officials often overstate the benefits of handwashing.
That’s not to say Lanard doesn’t believe in handwash-ing. She is, in fact, a big fan of the practice. But she’d prefer it if authorities stuck to the science – and says there isn’t that much evidence handwashing cuts down on flu transmission. (That doesn’t mean it doesn’t, just that there aren’t a lot of studies showing that it does. )
Lanard thinks public health messaging should suggest that it’s plausible that frequent handwashing reduces the risk of acquiring colds and the flu.
The author of a book on hygiene says public health messages about handwashing and self-inoculation should be synergistic. “I don’t think it’s an either-or thing,” says Dr. Bonnie Henry, author of Soap and Water and Common Sense.
Henry is the medical director of communicable disease prevention and control services at the British Columbia Centre for Disease Control. She says it can be difficult to get people to think about self-inoculation.
“I think it’s inevitable that you’re going to touch your face and you really need to make sure that you clean your hands regularly because that’s what’s going to protect you at the end of the day.
“I always say, ‘It’s not having bugs on your hands that’s the issue. It’s when you go to eat your sandwich or rub your eye. That’s when you’re going to get sick from it.'”
Alonso says it’s important to keep the issue in context. He doesn’t want to turn people into hypochondriacs.
While people can self-inoculate, it isn’t going to happen every time a person puts a finger into their mouth or rubs the bottom of their nose.
That said, when there is a disease outbreak, such as a flu pandemic, having people aware of the role they can play in triggering their own infections could be helpful in slowing the spread of disease.
Via: The Windsor Star
April 10, 2010
New study reports: hand gels are misleading, only killed 60 per cent of germs at best.
Last year, when swine flu hit, sales of some products rocketed by 70 per cent. Yet do hand gels really help? A study carried out in December 2009 by Ottawa University found that some brands that claimed to kill ’99 per cent’ of germs did not – at the very best they killed 60 per cent, and at worst just 46 per cent.
A dailymail report describes:
“The Medicines and Healthcare Products Regulatory Agency says it has had to investigate numerous hand-cleaning products for making claims that they can kill specific viruses such as swine flu or MRSA. They are not allowed to make these claims, because it gives the impression they have some medical effect. Gels can only really help kill everyday germs, such as those that cause the common cold. Yet few people realise that the hands have to be clean in order for many hand gels to work.
‘Like many cleaning agents, most hand gels will be less effective in the presence of protein matter, such as food, mud, faecal matter or blood,’ says Dr Ron Cutler, a microbiologist from Queen Mary, University of London. ‘You really need to wash off all visible signs of dirt before they will be totally effective.’ Many hand gels contain alcohol, which kills germs by attacking their outer membrane. For maximum benefit, a hand gel should contain at least 62 per cent alcohol – but no more than 80 per cent. This is because the gel should contain some water, as once the outer membrane of the bacteria or virus has been penetrated it is water that kills it.
But new research suggests that hands gels won’t protect against gastroenteritis or viral stomach bugs such as norovirus. Furthermore, a recent study by the Agri-Food and Biosciences Institute, Belfast, found that even Spirigel, the alcohol-based gel used in NHS hospitals, stops working within seconds of use. A non-alcohol gel offered much longer protection, killing viruses for up to 24 hours after it was applied.
Should we abandon alcohol hand gels? Non-alcohol gels work in a variety of ways. Byotrol, the gel used in this study, contains mainly water, but the gel forms an invisible layer that stays on the hands and literally pulls bacteria and viruses apart. Some others, such as No Germs, use chemical antibacterial agents or even essential oils. ‘When alcohol hand gels were first introduced years ago, it was so much better than anything else,’ says microbiologist Stephen Falder, who helped develop Byotrol. ‘But if you were going to start designing a hand gel now from scratch, you would abandon alcohol.’
He adds: ‘Alcohol stops working almost as soon as it’s dry, and does not give you residual protection.’ other experts disagree and say that while the effects of non-alcohol hand gels may last longer, alcohol is better at killing germs.
Professor John oxford, a virus expert from St Barts and Royal london Hospital, says he would always prefer an alcohol-based gel. ‘Yes, it might not work against things like norovirus, but norovirus is a very difficult bug to get rid of and nonalcohol gels won’t work against it either – little will. ‘The alcohol ones do work and certainly work against things like swine flu.’
Mr Cutler backs him up. ‘If my hands were dirty, I would wash them first with soap and water, using lots of agitation. ‘This cleans off all visible dirt. I would then apply an alcohol hand gel to get rid of any residual bacteria. ‘There are non-alcohol based products, some for example contain citrus oils, but I am not sure how strong an alternative these are. Washing your hands is the best option. ‘This should definitely be done after you go to the loo, after changing a nappy, after you sneeze, before you eat, before preparing food and after handling raw foods such as meat.'”
“The gold standard of hand washing is using hot running water and soap.”
“‘You need to wash both the palms and the finger tips and around rings of the fingers, as bacteria can lodge there,’ says Dr Anthony Hilton, a reader in microbiology from Aston University. ‘Then you should dry with a paper towel or hand drier. However if this is not available, then alcohol-based hand gels can be a very good substitute.'”
So, the essential is: do not consider hand gel sanitizers as a ‘safe’ alternative for hand washing!!!
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