There is a scene in the American sitcom Curb Your Enthusiasm that now appears surprisingly prescient, given the current anxiety about avian flu.
Larry David and Ben Stiller are being introduced on the set of The Producers when Stiller sneezes, and tries to catch the spray before extending a handshake.
David pointedly ignores the proffered hand, anxious not to become contaminated with Stiller’s germs, but in the process clearly offending him.
Even a few weeks ago we might have thought David’s behaviour unnecessarily rude, but with dead parrots making the fear of a flu pandemic more immediate, the way we treat the potentially infectious may have to change. For if avian flu “learns” how to infect humans, like other flu it will be spread in the particles of saliva expelled through coughing and sneezing. A sneeze can travel at 80 miles an hour, reaching distances of up to 30ft away. Just one sneeze can project 100,000 flu particles into the air.
How long those particles survive depends on the type of virus and the environmental conditions. Flu viruses can survive for more than 24 hours but for even longer indoors in winter because indoor air is more humid.
Professor John Oxford, a virologist at St Bartholomew’s and the Royal London Hospital, has looked at the most effective methods of preventing the transmission of colds and flu and says that, as well as vaccines and antiviral drugs, personal hygiene should be a priority.
“Over the past few decades there has been a worldwide general decline in levels of hygiene. We’ve seen the effects that this can have with MRSA, which focused attention on hygiene in hospitals. The levels of hygiene in hospitals were a reflection of the general situation and we all need to get our houses in order if we are to reduce the spread of infectious diseases.”
A man you’d expect to catch every cough, cold and nasty virus doing the rounds is Professor Ron Eccles, director of the Common Cold Centre in Cardiff. Yet, despite being surrounded by coughing, spluttering volunteers, he suffers only one or two colds a year, a fact he attributes to regular handwashing and avoiding touching his face.
“You’d have to be a hermit never to catch a cold, but in experimental conditions when healthy volunteers are kept with others who are suffering from common cold infections it has proven remarkably difficult to spread infection from one person to another. Most colds are caught at home, because of increased proximity and duration of exposure to the virus.”
In his view, it would be “rude” to offer a “mucus-laden handshake”. “If someone did whether I accepted it or not would probably depend on their status. In any case, I would wash my hands at the first opportunity.”
To catch a cold or flu virus, the mucus from the respiratory tract of someone infected has to get directly into your own respiratory tract. If an infected person coughs or sneezes near you, the risk is that you inhale their infected droplets; alternatively you touch a surface on which these droplets have landed, picking up the virus on your fingers, and then by rubbing your eyes or touching your nose, deposit the virus in your own respiratory tract.
Studies have shown that a cold or flu virus can survive on human hands for several hours. The virus can also survive up to 48 hours on non-porous surfaces such as a telephone, computer keyboard, doorknobs, kitchen utensils or toys. This is what makes handwashing so important. By washing your hands frequently and not touching your face, Professor Oxford says, you reduce the incidence of respiratory disease by 40 per cent.
The Health Protection Agency has not issued specific advice for avian flu; however, its general advice for avoiding infections includes washing your hands after blowing your nose, coughing or sneezing — you should wash more frequently if someone in your home or workplace is sick.
A cursory rinse under the taps is not enough: the HPA says we should wash using soap and warm running water, washing all skin surfaces thoroughly, including wrists, palms, back of hands, between fingers and under fingernails, and we should do this for at least 20 seconds before rinsing thoroughly and drying with a paper towel, clean fabric towel or air dryer.
The HPA also advises patting the skin dry, rather than rubbing, to avoid cracking and chapping, a common complaint among GPs and people who wash their hands more frequently than the rest of us.
In the flu pandemic of 1918 people began routinely to wear improvised facemasks and were told to avoid mixing in public places such as theatres and railway stations. There is little evidence, says Dr Anne Hardy, a reader in the history of medicine at University College London’s Wellcome Institute, that social sanctions extended beyond these measures but at the time people were used to the stigma attached to killer diseases such as tuberculosis, scarlet fever and polio.
“In the early 20th century, death and disease were still very much a part of daily life but since the Fifties, with improved living conditions and greater access to medical treatment, our attitude to disease has become somewhat distorted. We expect a cure to be made available, rather than actively trying not to get ill in the first place.”
But what if you find yourself in a Larry David social situation: do you shake hands, but make a concerted effort not to touch your face and then sneak off to wash your hands at the first possible opportunity? Avoid the handshake, Charles Mosley, the editor of Debretts, suggests. “It’s obviously slightly offensive to treat people like lepers but it’s also offensive knowingly to spread infectious diseases. As Zuleika Dobson said in Max Beerbohm’s novel: ‘Death cancels all social obligations.’ I would add that the risk of death may not cancel them entirely, but it certainly whittles them down. If shaking someone’s hand put me at risk of contracting a potentially fatal disease, I wouldn’t shake it, out of politeness.”
If Stiller had just sneezed, and not tried to catch the spray with his hand, then David might have avoided the offending germs anyway. If you are on the receiving end of a sneeze, a scenario familiar to anyone who uses public transport, you won’t necessarily pick up the offending virus, says Eccles. “In that instance, you will normally escape a cold, as our defences are usually effective and any viruses are trapped in nasal mucus and washed to the stomach , where they are inactivated. The danger is from particles entering through the eyes, from where they are washed to the nose via the tear duct. So if someone sneezes, try to turn away and close your eyes.”
Meanwhile, to avoid spreading their germs, Professor Eccles says sneezers should cover their nose and mouth with a tissue thick enough that it doesn’t break up on use and dispose of it immediately.
The SARS outbreak in 2003 began to raise consciousness of what one American health official called “good respiratory etiquette”. The increase in levels of hygiene in the countries that had SARS led to a “detectable” decrease in levels of flu, says Oxford, as people began wearing masks in public places (although scientists believe that the viruses that may be the cause of SARS are so tiny that they can easily pass through such barriers) and disinfecting shared equipment such as telephones, computer terminals and doorknobs.
Already there are several websites offering face masks, goggles (to prevent viruses entering the system through the eyes) and portable hand sanitisers to anyone preparing to avoid avian flu.
At the end of the Second World War the Department of Health tried to keep the nation “fighting fit” with a poster campaign warning that “coughs and sneezes spread disea- ses” and the dictat to “trap the germs in your handkerchief”. Nowadays health professionals regard handkerchiefs as un- hygienic and the current Department of Health’s guidelines for flu and colds is to use disposable tissues.
If the pandemic becomes a reality, the guidelines will become more hardline, and could include avoiding handshakes and other forms of social contact.
SCENARIO 1: TOILET DOOR HANDLES
Q: A colleague assumed to have flu sneezes into his hands and then uses the office toilet. He does not wash his hands afterwards. You go to the toilet, wash your hands thoroughly and then exit, thereby touching the same door handles that he has also handled. Does the door handle present a health risk for influenza? If so, how can one minimise it?
A: Yes, there is a risk but it can be reduced. The influenza virus cannot be transmitted simply by someone going to the toilet and not washing his hands; there must be virus on his hands which can then be passed on. There are two types of influenza responsible for most infections: A and B. Both viruses last for 24-48 hours on hard, non-porous surfaces such as stainless steel and plastic but survive for less than 8-12 hours on cloth, paper and tissues.
Hard surfaces (eg, kitchen worktops, door handles) should be cleaned frequently, using a normal cleaning product. One option would be to clean the door handle, wash hands and then exit. People with suspected flu should stay at home.
Adapted from advice given by the Health Protection Agency
SCENARIO 2: SNEEZES ON A CROWDED BUS
Q: You are on a crowded bus and someone close to you sneezes, without covering their nose and mouth. Is there anything you can do to minimise your chances of catching an infection, eg, wear a mask, get off at the next stop and wash your hands before continuing your journey?
A: Catching the infection from someone in the vicinity will depend on how close you are to the person sneezing, air humidity, the amount of virus present and whether you are susceptible to the infection, ie, if you have suffered from it before and gained immunity or if you have been vaccinated. If someone does sneeze near you, make sure you wash your hands and face as soon as appropriately possible.
Adapted from advice given by the Health Protection Agency
Health Protection Agency: www.hpa.org.uk
Department of Health: www.dh.gov.uk
Article Source: http://timesonline.co.uk