1. Sources and spread of pathogens in the household
Infectious diseases are one of the leading causes of death worldwide and account for around 4% of deaths in developed countries (Bloomfield et al. 2006). However, it is only in the past two decades that household hygiene has received due attention. Nevertheless, infections can be transmitted in the home. The reason for this is that more and more patients are being cared for on an outpatient basis in the home environment and the proportion of old people who are at risk of infection is increasing significantly due to demographic changes (Bloomfield, Exner, Dietlein 2008, Scott et al. 2010). In addition, the household and the family are the central elements of a society, as there is a dynamic interaction between the household, its members and communal institutions such as schools, Workplaces and facilities for communal catering exist. Against this background, it has been recognized that hygiene in the household must be given greater importance again and that joint responsibility for this in the family / household and society is important (Bloomfield et al. 2009).
The aim of hygiene in the household is not to eliminate all microorganisms, but to reduce them to an extent where they can no longer infect or inactivate pathogens. In the household, a distinction must be made between risk areas and non-risk areas. The former should be given special attention in the sense of a risk-based approach as a strategy of targeted hygiene (Bloomfield et al. 2006, Bloomfield 2007, Bloomfield et al. 2008). We have to learn to assess when, in everyday use, hygienic cleaning measures are specifically required in which places.
Possible sources of infection in the household include animate and inanimate sources (reservoirs). Animate sources include family members, but also pets, inanimate sources include contact surfaces, food, moisture reservoirs and household utensils.
The transmission of infections in the household can take place in different ways:
- Direct contact between humans and animals via the hands is a common route of infection.
- The bacteria in one’s own body can lead to infections through smear infection if they get into primarily unpopulated areas of the body; here personal hygiene plays an important role in avoidance.
- Gastrointestinal infections can be transmitted through contaminated food.
- There is the possibility of indirect transfer via surfaces; many pathogens can survive on surfaces for a long enough period to pose a risk of infection under certain circumstances (Bloomfield and Scott 1997). In particular, the contact surfaces for hands and food as well as cleaning utensils play a major role.
- Infection via the air through skin flakes or droplets when sneezing, coughing or speaking is also possible.
- Insects and pets can play a role in the transmission of infections in the home.
The risk of transmitting pathogens depends on a number of factors:
- Infection dose (number of pathogens transmitted),
- pathogenic potential of the pathogen (virulence),
- Susceptibility of the host: newborns / infants, old people, pregnant women and people with weakened immune systems are at increased risk of infection,
- Density of housing in the household.
The number of possible pathogens can be reduced by the following measures:
- Cleaning: hand washing; Cleaning of cooking and eating utensils and surfaces.
- Heat: for laundry, cleaning utensils, food.
- Chemical disinfectants.
2. Hand hygiene
Various bacteria occur on human skin as normal skin flora. We call them resident skin flora (constant skin flora). This takes on a certain protective function because it counteracts the colonization of pathogens.
The so-called transient skin flora (contact flora) occurs only intermittently and in some people on the skin; it is constantly re-acquired from the animate or inanimate environment. An example of this would be the presence of Staphylococcus aureus bacteria in the nasal vestibule. Depending on the contact with our environment – surroundings, fellow human beings, animals – our germ flora changes in quantity and composition. And this also changes the risk of receiving potential infectious agents and passing them on without our being aware of it.
On the one hand, the hands are the most important transmission route for infectious diseases. Thus, on the other hand, hand hygiene is the most important measure to prevent the transmission of pathogens. This path of infection is the easiest to control – provided that hand hygiene is trained regularly and in an understandable manner; this should already be anchored in the school curriculum (Bloomfield et al. 2008). S. Bloomfiled (2007) describes risk-based hygiene management in the home environment in detail; Here, critical control points are determined using a risk assessment based on the evaluation of microbiological data in the infection transmission cycle (degree / frequency of contamination and probability of transmission): hands, hand and food contact surfaces and cleaning utensils / towels.
The transmission to the mouth, eyes or nose can be counteracted efficiently by adequate hand washing. In the majority of cases, it is sufficient to wash your hands thoroughly with soap at home. This means that hand disinfection with alcohol is only required in exceptional cases – for example if there are infectious roommates / animals or family members with a weakened immune system. Washing your hands is strongly recommended:
- after using the toilet,
- after contact with pets and their paraphernalia,
- after contact with other people,
- before the meal,
- before contact with food, during the preparation of meals,
- after contact with body fluids,
- with visible contamination,
- before administering medication,
- before and after changing dressings,
- before inserting contact lenses,
- after activities that are prone to contamination (e.g. cleaning the toilet, preparing raw meat, eggs),
- after playing on the floor or outdoors.
Adequate hand washing includes:
- Sufficient drinking water quality / running water, soap and water
- the subsequent complete drying of the hands with a clean towel.
A washing time of 30 seconds to 1 minute is necessary to reduce the number of germs sufficiently. The thumbs, backs of the hands and fingertips – nail areas! – as well as intermediate finger areas are included. Care should be taken to use skin-friendly soap products, which can be more easily spread on the hands than liquid soap.
Careful drying with towels that are changed regularly, as well as the use of skin care creams from tubes, counteracts drying out. Towels are to be hung up to dry after use. Short fingernails make hand hygiene easier. Regular, consistent hand washing is one of the best ways to prevent the spread of infectious diseases.
If hygienic hand disinfection is required in exceptional cases, approx. 3 ml of an alcoholic hand disinfectant should be poured into both dry hands and rubbed in evenly for at least 30 seconds. Water and soap may only be used after this, as otherwise the disinfection process would be stopped prematurely.
3. Household hygiene and contact areas
Depending on the different reservoir, different hygienic procedures are required to counteract the spread of pathogens.
Basically, surfaces in the household that can be safely cleaned with water – preferably hot – and cleaner and then dried do not have to be disinfected. The mechanical component during cleaning, for example by means of brushing or thorough rubbing, is decisive for the effect.
Utensils for wet cleaning such as dishcloths, mops, mops, washcloths must be restored to a hygienically clean and not just optically clean condition every time after use – at least every day. This can be done, for example, by washing in the washing machine at at least 60 ° C or by boiling it out. Washing with soap and water is relatively ineffective (Scott and Bloomfield 1990). For example, sponges that are not washable and that take a long time to dry after use are not suitable for the kitchen area.
Separate or freshly washed cloths must be used for the various household areas such as the bathroom and kitchen. Subsequent drying of the utensils after washing and use is particularly important in order to prevent the reproduction of the remaining organisms at room temperature.
The use of disinfectants – which lead to the killing of microorganisms and not only to a reduction in the number of germs as with cleaning – should be limited to exceptions such as unsafe surfaces to be cleaned or in the presence of infectious (e.g. diarrhea, vomiting, carriers of resistant pathogens such as multi-resistant Staphylococcus aureus Strains) or immune-weakened (e.g. HIV, leukemia) family members.
However, disinfection only offers additional security if the user is familiar with the selection and use of disinfectants (disinfectant list of the VAH). Preferably the contact surfaces for hands and food as well as areas heavily contaminated with body secretions such as vomit should be disinfected (after previous cleaning). Particular attention should be paid to hand disinfection after removing heavy soiling. If necessary, disposable gloves must be worn.
Carpets and carpets should be vacuumed regularly. They are to be assessed as an unfavorable floor covering for allergy sufferers and those with immunodeficiency.
In general, sufficient and regular ventilation counteracts the growth of germs – for example the formation of mold – in damp areas, but also in other household areas.
Reservoir areas such as toilet bowls, wash bowls, draining boards or diaper pails have only a relatively low risk of transmission under normal conditions of use. They should be cleaned regularly.
Contact surfaces for hands, food and drinking water – such as work surfaces in kitchens, eating and cooking utensils, wash basin fittings – must be carefully cleaned after contact with contaminated materials. This is done with hot water and detergent, which must then be rinsed off thoroughly. Simply wiping it with a cloth dampened with a cleaning agent is not enough from a hygienic point of view. Contact surfaces for hands such as taps, toilet seats / flush buttons, sinks, bathtubs or handles on refrigerators should be cleaned regularly with a cleaner – especially if they have been soiled by unclean hands (such as after processing raw meat). Hands must be washed after contact with contaminated material.
Areas should be kept in a dry state, as moisture reserves promote the multiplication of pathogens.
Floors, walls, furniture, etc. generally bear only a low risk of transmission. They should be cleaned regularly and kept dry.
Shower heads that have not been used for weeks carry the risk of colonization with Legionella and Pseudomonas aeruginosa. Before you shower for the first time, they should be rinsed thoroughly by turning the hot water on and letting it run off. The hot water should have a temperature of 60 ° C in the warm water boiler and 55 ° C in the peripheral pipes and in the water outlet in order to counteract colonization. Limescale deposits should be removed regularly.
Parents should note that communal toys that children put in their mouths can be carriers of infection – especially if several children are playing with them. These toys should at least be cleaned and, if necessary, disinfected.
Body fluids such as feces, urine or vomit should be removed immediately using disposable paper and the surfaces should be cleaned thoroughly – preferably with subsequent disinfection if they come from infectious people.
4. Food hygiene
The majority of food poisoning cases in Europe occur in the home. Most cases can be traced back to inadequate preparation or incorrect storage of food (Roberts 1990, Scott 1996). Cross-contamination via the hands or preparation surfaces is often causally involved.
Raw foods such as raw meat, eggs, fish and poultry are particularly at high risk of contamination. The cutting board and all surfaces / utensils that have come into contact with it must be thoroughly cleaned immediately after preparation or preparation by washing with hot water and cleaning agent and then rinsing off. We recommend using separate cutting boards for raw meat / poultry and other foods. It can also be cleaned in the dishwasher at at least 60 ° C. The cutting board must not be washed in the sink for dishes or salads. Hands must be washed immediately after preparation; Contact surfaces such as the faucet or handles on the stove that have become contaminated must be cleaned. Disposable towels are preferred.
Cloths must not be kept damp in the kitchen area. They have to be hygienically clean and not just optically clean; this must be ensured through appropriate laundry hygiene.
In order to safely kill the pathogens such as salmonella and E. coli O 157 (EHEC pathogens; enterohaemorrhagic Escherichia coli strains) occurring in food, a temperature of 70 ° C must be reached for at least 2 minutes in the center of raw meat and egg products and being held. This means that it is not enough to heat the product for 2 minutes, it is important that it reaches at least 70 ° C for 2 minutes everywhere (at 65 ° C 10 minutes are required, at 60 ° C 45 minutes). This is particularly important for frozen foods. With microwave ovens, ensure that the food is heated evenly by turning or stirring. Meat should no longer be red or pink and no longer show bloody juice.
Equipment for the preparation of food must be cleaned regularly. Utensils that were used in the preparation of raw foods must not be used when serving (e.g. knives, forks, plates).
In particular, wash your hands before touching food that has already been cooked. Food that has already been cooked must not come into contact with raw food. All preparation areas must be kept hygienically clean.
Cooked food should be cooled as quickly as possible so that no microorganisms can multiply in them. They should be stored in the refrigerator or freezer. The temperature of the refrigerator should be between 1 and 5 ° C and that of the freezer at minus 18 ° C (Eley 1996). Food should only be stored in the refrigerator for a limited period of time; pay attention to the expiry dates. Thawing frozen food should be done in the refrigerator.
Raw and cooked or perishable foods such as butter should be stored separately in the refrigerator; Covering may be required. Cooked foods should be stored above raw ones. Meat / poultry should be frozen in safe containers. Moldy food should be thrown away completely. Thawed food should not be refrozen unless it is cooked beforehand. Regular cleaning of the surfaces in cooling devices must be ensured.
If possible, people suffering from acute diarrhea or vomiting should not prepare any food for other people.
5. Laundry hygiene
In normal households, the risk of infection transmission via laundry is low compared to the risk posed by contact surfaces for hands and food.
Washing with hot water (at least 60 ° C) and detergents (preferably bleach-containing heavy-duty detergents (Exner, Simon 2011)) or at lower temperatures (40-60 ° C) with the addition of disinfecting laundry additives (VAH list) decontaminates the laundry effective in the household. This is the way to wash heavily soiled laundry, underwear and towels, or laundry for the food area. The rest of the laundry, such as clothing with the exception of underwear, can be washed at lower temperatures. Towels, dishcloths and other textiles that are used in the preparation of food should be washed separately from the rest of the laundry.
Laundry contaminated with pathogens or in the case of immunocompromised family members should preferably be washed at 90 ° C or with the addition of disinfecting laundry additives at 60 ° C.
Basically, the machine should be emptied as soon as the washing program has ended. The laundry should then be completely dried because moisture promotes the growth of remaining bacteria and fungi. A hot wash cycle should be carried out once a week in order to counteract the formation of biofilm (slime formation in hose systems with bacterial growth).
Care should be taken to clean hands after contact with dirty laundry.
6. Waste hygiene
Waste bins should be kept dry and clean. It is preferable to use containers with foot control so that hands are not contaminated during use. Needles should be disposed of in such a way that nobody can injure themselves on them. Hands should be washed after handling rubbish. Outdoor rubbish bins should have tightly fitting lids to prevent insects and animals from being attracted.
7. Personal hygiene
The majority of the body is colonized with normal bacteria. Since these have a protective function against colonization by pathogens, general personal hygiene should not lead to a reduction in these residents. When showering or bathing regularly, however, care should be taken that utensils such as bath towels, nail brushes etc. can spread pathogens. To avoid this, they should be dried as soon as possible after use, so that there is no increase in the number of germs on them. Regular washing in the washing machine should be carried out.
8. Hygiene in households with pets
Many people experience a significant improvement in their quality of life by keeping animals. Pets live in almost every second household in Germany. Pets can, however, be carriers of pathogens such as Salmonella and Campylobacter and trigger allergic diseases (especially through cat secretions) (Exner and Engelhart 2002; Wall et al. 1996).
In order to prevent a possible risk of infection in the domestic environment with animals, certain hygiene measures must be observed:
- Pets should be properly vaccinated against diseases.
- They should be regularly monitored by a veterinarian.
- It is important to ensure that the respective pet is fed a species-appropriate diet (e.g. prevention of dog tapeworm infestation; if possible, avoid feeding raw meat, especially pork and poultry).
- They should not be kept and fed in the bedroom or children’s room – especially for people with allergies – or in the kitchen.
- Your quarters and “toilets” should be cleaned daily.
- Pet care utensils should not be cleaned in the kitchen; cleaning utensils specially used for this purpose should be used.
- Feeding utensils and the area where the animals are being fed should be cleaned thoroughly and regularly.
- If disinfection is necessary (especially in the case of sick animals), chemical disinfectants from the VAH list can be used.
- The contact of pets with food preparation surfaces is risky.
- Behaviors that encourage the transmission of infectious agents (such as licking the face) should be avoided.
- Wash hands after contact with animals, especially before eating.
- Body fluids from pets should be removed immediately and the surfaces cleaned with a disinfectant.
9. Hygiene in groups of people with reduced resistance to infection
The proportion of people over 65 years of age in the population is constantly increasing. This also increases the proportion of people with a reduced resistance to infection. Other “risk groups” are newborns / premature babies and people who take medication such as corticoids or who have diseases that affect the immune system.
When caring for newborns / premature babies and infants, the following points must be observed in particular:
Disposable diapers should be packed in a plastic bag and disposed of in the trash.
Surfaces that may be contaminated with stool when changing diapers must be cleaned using a disinfectant.
Reusable diapers should not be washed out in the kitchen; vessels should then be cleaned using a disinfectant. The laundry must be treated according to the rules of laundry hygiene (see above) and should preferably be washed as whites.
Old and immunocompromised people in particular should ensure that foods such as meat, fish and eggs are cooked through and follow the rules of food hygiene.
With regard to further aspects relating to immunocompromised patients, reference is made to the article by Kaufmann et al. (2002) referenced.
10. The infected family member
Family members with acute infections such as diarrhea / vomiting diarrhea, wound, skin or eye infections should pay particular attention to good hand hygiene. In particular, hands should be thoroughly washed or disinfected after using the toilet or after touching infected parts of the body. The infected people should not prepare food for other people. Separate towels are to be used for infected and uninfected family members.
In the case of blood-borne diseases such as hepatitis B / C or HIV, gloves should be worn if blood contact is to be expected. After removing the gloves, the hands must be disinfected. Surfaces contaminated with blood must be disinfected promptly and cleaned; gloves must be worn here. Toothbrushes, razors, or items that can easily be contaminated with blood should not be shared by family members.