Risk Classification

A home is packed with places where germs can breed and spread easily. Four main areas have recently been classified as being at risk from contamination.

- Reservoirs. These are all the humid places in a house where germs love to breed such as U-bends, toilet bowls, sinks and draining boards. They are frequently contaminated but, because of constant flushing and the fact that they are contained areas, regular disinfecting is enough to stop the spread of germs.
- Distributors. All the items used for cleaning, including sponges, dishcloths, tea towels, floorcloths, flannels, towels and brushes, harbour micro-organisms and promote their growth. They are constantly damp and therefore always contaminated, which means they are ideal sources of cross-infection as every member of the family uses them. With such a high contamination risk frequent cleaning, preferably after each use, is a must.
- Surfaces. Those that come into contact with hands and food. These are carriers that encourage cross-contamination by collecting and spreading all sorts of germs. Hands constantly touch the surfaces of handles, toilet seats, bathtubs, telephones, etc. Hands and food come into contact with chopping boards, work surfaces, fridges and kitchen utensils.
- Others. This group includes floors, carpets, dining and bedroom surfaces, furniture and other objects less exposed to contamination.

Home

According to the EPA (Environmental Protection Agency), Americans spend an average of 90% of their time indoors. This surely poses a number of questions about the risks linked to sedentary lifestyles but also shows that hygiene in the home takes on a greater importance. In Europe, the proportion of time spent indoors is "only" 75%. In addition to sleeping, the house is also a place of communication and education, etc. Television, PCs, the Internet and every sort of modern technology is at hand to supply everything that could be wanted without having to go out. Hospitalization at home, which is becoming more common, as well as the growing number of elderly have led to a greater need for hygiene awareness as these people are particularly sensitive to infection.

Hygiene measures are aimed at reducing surface contamination, including the hands, to levels that are not detrimental to health. This does not mean creating a sterile environment; individuals will continue to be exposed to pathogenic agents which are part of the living world, but the risk should be minimized to avoid endangering public health.

Kitchen

Although the kitchen sink harbours 100000 times more germs than a bathroom or toilet, most people consider the latter to be the most contaminated part of the house. A number of facts illustrate the importance of good hygiene in the kitchen :

- It is the room most frequently used by the whole family.

- 40% of food poisoning cases originate in the home and not in restaurants. - Studies carried out in the last few decades have shown that pathogenic agents are found in most homes. - Preparing a chicken that contains Salmonella, which is quite common, leads to the entire kitchen being contaminated via utensils, work surfaces, sink, kitchen doors, fridge, oven and of course the hands of the person who handled the chicken.

Salmonella: bacteria responsible for salmonellosis, a common zoonosis, and a cause of food poisoning (re-coloured).

Important advice
- Wash hands thoroughly before touching food. This is even more important after having touched a pet or used the toilet. Use waterproof plasters to cover cuts.
- Make sure that the sink and surrounding areas are cleaned regularly.
- Keep the fridge at a constant temperature of between 0 and 4°C and clean it, as well as cupboards, as often as possible. Put raw meat in a dish or on a plate.
- Always check that cleaned surfaces such as worktops and fridges are thoroughly dry before putting food down.
- Wash and disinfect the bin and the area around it (in case of spatters). Bins contain high concentrations of bacteria so it is important to empty them every day and to wash them regularly.
- Towels and cloths used in the kitchen should be changed frequently and always washed carefully. The survey mentioned previously showed that while one in three people changes them every day and 57% at least one a week, 21 million Europeans (7%) only change kitchen linen if it is really dirty or when they think of it!

- Sponges require particular attention. Because of the ambient moisture, bacteria thrive in the very tools that are considered best for cleaning. To render this potential source of contamination less effective, sponges should be changed quite frequently and used with anti-bacterial washing-up liquid, even soaked with it between use. For quick cleaning jobs, it may be wiser to use disposable wipes.

Listeria monocytogenes cross-section (re-coloured).

Tips when going away
- Make sure that perishables are disposed of. Get rid of crumbs and other debris that could
  attract insects and encourage bacteria while you are away.
- Wash down work surfaces.
- If the refrigerator is switched off, clean and dry it, and leave the door open.
- Wash towels and disinfect sponges and brushes around the sink.

Bathroom

The warm and damp atmosphere of a bathroom encourages bacteria growth. Soapy water loaded with bodily bacteria collects in thin layers on the surfaces of the shower, the bath and the shower curtain. If the curtain is made of fabric then it may be machine-washable at a low temperature.
Face flannels remain popular, but their almost constant humidity makes them an ideal breeding ground for germs. As a result, they should be changed regularly and be preferably made from thin material that dries quickly.

Handy tips
- Clean and disinfect baths, sinks and toilets regularly.
- Don't forget doors, handles, toilet rims and taps.
- Hang towels up to dry after use.
- Give each family member their own towel.
- Air the room regularly to help disperse steam.

Laundry

One group of scientists recently looked at the risk of laundry contributing to the spread of infectious disease. It is generally well known that toilets and kitchens are high risk areas for germ growth, but laundry is rarely mentioned as a potential source of contamination. Recent research has shown that germs can spread from one fabric to another and from the washing-machine drum to the next load. Even our hands can help the spread when handling wet clothes that have just been washed. For years it has been accepted that very hot water is necessary to kill germs in the washing, but our wish to preserve modern textiles has led us to use ever lower temperatures and, in our efforts to consume less energy, our environmental concerns have also led to a reduction in washing powder. The way that we do our washing today is not always sufficient to destroy germs in clothes. Some germs from food, the body or other sources can survive a wash cycle and spread via our hands to other surfaces. Among them are staphylococcus aureus and klebsiella pneumoniae, two types of common bacteria that are most difficult to eradicate.

Some microbiologists believe that the numbers of bacteria capable of surviving a wash are on the increase. One reason for this rise is the use of cooler water temperatures. Washing at 40°C showed 500 times fewer bacteria than on the dirty clothes, while the same load washed at 30°C only contained 10 times fewer.

The risks of contamination are minimal for a healthy family but convalescents could transmit their germs or be vulnerable enough to contract an illness. In addition, drying in fresh air rather than a tumble-dryer increases the survival rate of bacteria because the clothes stay damp longer.

Some simple precautions can effectively help control the spread of potentially pathogenic germs :
- Before doing the washing, always separate "risk" items such as underwear, towels, baby clothes, etc. About 30% of the population sort their washing which, although the figure varies between countries, is a small proportion considering the potential risk of not sorting.
- Wash hands in hot soapy water after placing the laundry in the machine and again after handling damp washing. Washing hands after handling dirty washing is quite common, washing hands after taking wet clothes out of the machine is rare because clean washing is often mistakenly seen as being germ-free.
- Look out for washing products that actually are effective against germs.
- Wash dirty clothes as soon as possible and especially damp items such as towels.
- Don't wait for clothes to get thoroughly soiled before doing the laundry. The more germs on a garment before washing, the more remain afterwards.

Household allergies

Housedust is a significant source of allergens (substances responsible for causing allergic reactions in some people) of which dust mites are the most important. Dust mites are tiny animals, invisible to the naked eye, which live in fabric, wool and feathers. Dust mites love heat and humidity. They eat the tiny bits of skin that humans shed every day (desquamation). They are often found in pillows, woollen blankets, cuddly toys, etc.

Beds are ideal for them because of moisture from perspiration, and they can feed on this. Although dust mites can't fly, making the bed, shaking the bedclothes and plumping the pillows, or vacuuming, sends them into the air where they circulate around the room.

Inhaling enough dust mites in high enough doses can cause various allergic reactions, particularly respiratory ones such as rhinitis (sneezing fits, blocked nose, runny eyes) and asthma.

Asthma is a bronchial condition resulting from an acute reaction to irritants. This hyperactivity leads to constriction of the bronchial muscles and inflammation of the bronchial wall. Under certain conditions such as stress, illness or allergy, the bronchial muscles contract rapidly, restricting the airway. Typical symptoms of asthma are breathing difficulties associated with coughing and wheezing. To avoid such attacks, in addition to basic treatment, measures should be taken to prevent the cause.

Dealing with dust mites
Dust mites are found everywhere, even in really clean houses. By reducing their numbers or containing their presence, allergic reactions become less severe or non-existent. There are several ways of dealing with dust mites, that are often best combined :

On peut par exemple :

- Washing at high temperature, i.e. above 55°C.   Products are also available (acaricides) that kill dust mites.

- Controlling their development by reducing the humidity and heat in a room so that dust mites find it hard to survive and multiply. - Trapping them with dust mite covers on mattresses and pillows.

- Eliminating them with special wipes that are very effective in catching these allergens; even a damp cloth works quite well. Vacuuming is more effective than brushing, as long as it is fitted with a dust mite filter, otherwise the tiny particles are easily recycled in the air.
- Reducing the areas of fitted carpet around the house.