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Coping with floods, cleaning up afterwards – and staying healthy This leaflet has been put together to provide advice and background information on staying free from infectious disease during and after flooding, including cleaning up the home after the flooding has subsided. This briefing material has been produced for healthcare professionals, the media and others who are looking for some background understanding of hygiene issues related to flooding and/or are responsible for providing guidance to the public on coping with hygiene issues associated with flooding. Background Flooding is the most common type of natural disaster world-wide – and accounts for 40% of all natural disasters. Although for hundreds of millions of people living in lowland river-line or coastal areas in South East Asia, flooding is a common occurrence and an accepted part of life, in areas such as Europe and North America, extensive flooding has, until recently, been considered a rare phenomenon. In the last 5/6 years however, incidents of serious flooding in Europe and the US have increased. In Prague, in 2002, more than 35,000 people were evacuated from their homes when the Vltava River burst its banks. In 2003, there was significant flooding in Florida and Jamaica following the hurricanes which hit the area, whilst the city of New Orleans was very severely affected in 2005. In the UK five million people live in places with a risk of flooding. In the last few years there have been serious incidents of flooding in the Severn valley and also in Carlisle, whilst in 2007 we have seen two serious incidents of flooding, firstly in Yorkshire and later again in the Severn valley, but also in the Thames valley. Flooding – what are the risks of infectious disease? Although, for countries such as the UK, the risk of infections and illness after local flooding is considered to be generally low, and in the past the number of reports of illness, gastric or otherwise, after flooding has been minimal, the extent of recent flooding problems such as those in the UK is unprecedented which means that it is impossible for local authorities to give a true assessment of the extent of the infectious disease risk. This means that we have to assume that the risks are finite and take preventive measures to protect against infectious disease. Protecting family members who are at increased risk of infection1 is particularly important. Once one 1 Up to 1 in 7 people in the UK community is considered at increased risk of infection. The largest proportion of these people are the elderly who have generally reduced immunity to infection which is often exacerbated by other illnesses like diabetes, malignant illnesses, etc. It also includes the very young, and patients discharged from hospital, taking immuno-suppressive drugs or using invasive systems etc. All of these groups, together with family members who carry HIV/AIDS, are increasingly cared for in the home. member of the family becomes infected, the infection can spread very rapidly to other family members and into the community. Flood water affecting the home or other property (and the surrounding environment) is quite likely to be contaminated with sewage and other organic material such as animal faeces, rotting vegetation etc. from the environment and, therefore, it must be assumed that it may be contaminated with human or animal pathogens (either bacteria or viruses). A July 2007 study of flood water samples taken from swamped streets in Tewksbury showed the presence of coliforms. Although it is likely that pathogens entering floodwater from sewage or other sources will become much diluted, there is a small risk that people may contract a stomach bug if they come into direct (hand to mouth) contact with contaminated water or if they handle food with contaminated hands. It must also be borne in mind that floodwater and sewage when it subsides leaves a muddy deposit, both indoors and in the immediate environs of the home. It may take a long time to dry out after flooding, especially in humid climates, and moulds can establish and grow on surfaces causing spoilage of items. Germs deposited on these surfaces will gradually die out, but whereas some pathogens e.g. Campylobacter die rapidly, others such as norovirus and C.difficile can persist and remain infectious for days, weeks or even months. These organisms can be transferred from contaminated surfaces via hands directly into the mouth or onto food, or indirectly via hands into food. As it is not always clear whether flood water, environmental surfaces and in some cases tap water, are contaminated with pathogens or not, the basic advice is to assume, unless otherwise advised, that they are and take rigorous hygiene precautions to prevent spread of infection in the home. Basic Hygiene Precautions Key hygiene precautions in the event of flooding are as follows and appropriate hygiene measures are described in more detail below: Wherever possible, avoid coming into direct contact with floodwater. Do not let children play in floodwater and wash their hands frequently, particularly before snacks and meals. Decontaminate floodwater-contaminated toys before allowing them to be used again. If it is necessary to come into contact with floodwater, wear waterproof gloves (such as household cleaning gloves) and wellington boots. Cuts and other open wounds should be covered with a waterproof plaster. Wash hands thoroughly with hot water and soap, especially after contact with floodwater or taking part in cleanup/decontamination activities - and ALWAYS before handling or eating food, or feeding children. Ensure that items or surfaces which may have been in contact with flood water, including food contact surfaces (countertops, chopping boards and cleaning cloths, eating utensils (cutlery and crockery)) and hand contact surfaces (door handles, tap handles, stair rails etc.) but also toys, clothes and soft furnishings, are decontaminated before use. Food or drink suspected of being contaminated should be thrown away. Rigorous standards of hygiene are important during handling and preparation of food. Drink only water which is “clean” This means drinking bottled water or water which has been decontaminated by boiling of treatment with a disinfectant. Where the drinking water supply is either interrupted or contaminated, it is important to take precautions for formula-fed infants. Anyone who has accidentally swallowed or been in contact with contaminated Page 2/9 water or sewerage who develops diarrhoea, fever or abdominal pain in the following 10 days should seek medical advice from their GP or (for UK) from NHS Direct on 0845 4647. Read on for more detailed guidance. Please note that there is some repetition in the following material, to ensure that, for people who may refer to only certain sections, the information they obtain is comprehensive: Hand Hygiene The hands are “critical control points” for infection transmission in the home, since they come into direct contact with known “portals of entry” for pathogens (mouth, nose and conjunctiva of the eyes). For pathogens such as norovirus the “infectious dose” (the number of virus particles needed to cause infection) can be very small (110 particles). Hands are thus a key last line of defence against the ingestion of pathogens, which is why hand hygiene is so important. During flooding and during the clean up operation hands can become contaminated by direct contact with flood water. Hands can also become contaminated by contact with surfaces which have been contaminated with flood water where some pathogens can survive on these surfaces even after they have dried out. Since handwashing is intended to prevent transfer of pathogens from floodwater directly into the mouth, or onto food which is then eaten, key times for handwashing are: After clean up activities associated with flooding. Before preparing and handling cooked/ready-to-eat food. Before eating food or feeding children. Hand hygiene is also important: After contact with potentially contaminated surfaces. How to wash hands: Handwashing “technique” is very important. Rubbing with soap and water lifts the germs off the hands, but rinsing under running water is also vital, because it is this process which actually removes the germs from the hands. The accepted procedure for handwashing is: Ensure a supply of liquid soap, warm running water, clean hand towel/disposable paper towels and a foot-operated pedal bin. Always wash hands under warm running water. Apply soap. Rub hands together for 15–30 seconds, paying particular attention to fingertips, thumbs and between the fingers. Rinse well and dry thoroughly. In situations where soap and running water is not available an alcohol- based hand rub or hand sanitiser should be used to achieve hand hygiene: Apply product to the palm of one hand. Rub hands together. Rub the product over all surfaces of hands and fingers until your hands are dry. Note: the volume needed to reduce the number of germs on hands varies by product. Page 3/9 During the flooding, things are likely to be very chaotic, and even very basic hygiene measures such as handwashing may not be possible due to lack of clean water. In this situation one very simple thing which people can do which can significantly reduce the risk of disease is to avoid putting their fingers to their mouth. General cleaning up inside your home On returning home after a flood, it is important to be aware that flood water may contain harmful organisms and that small numbers of these organisms will remain on floors, walls and other surfaces after the floodwater subsides: Wear wellington boots and waterproof gloves and apron during cleanup. Cover any open cuts with waterproof plasters. Keep children and pets out of the affected area until cleanup has been completed. Remove as much silt and water as possible from the home. Where there are floorboards the space under the ground floor may need pumping out. Good ventilation and heating of the home will speed up the drying process and prevent mould growth. Pathogenic bacteria, viruses and protozoa also die out more rapidly on dry surfaces. Remove and discard all soft furnishings and fittings (wall coverings, rugs, mattresses, carpeting, carpet underlay, upholstered furniture, cosmetics, stuffed animals, baby toys, pillows, foam-rubber items, books, and paper products) that are damaged beyond repair. As soon as possible, transfer all refuse to secure plastic bags or other containers to prevent the spread of germs until refuse can be taken away All hard surfaces (walls, hard-surfaced floors, household surfaces and furniture) should be hygienically cleaned (see below for directions for hygienic cleaning of surfaces). Be particularly careful to disinfect surfaces that may come into contact with food, (e.g. work surfaces, food storage shelves, refrigerator surfaces etc) and surfaces which come into contact with the hands (e.g. door handles, tap handles, toilet flush handles, and stair rails). Areas where small children play should also be cleaned and disinfected. Allow all surfaces to dry thoroughly – good ventilation and heating will speed up the drying process. For those items which are not irreparably damaged, but which cannot be washed or dry cleaned such as mattresses or upholstered furniture, air dry them in the sun and then if there is no risk of colour damage spray them thoroughly with a solution of bleach. Steam clean carpeting if possible. For areas where mould has already begun to develop, a concentrated solution of bleach (see hygienic cleaning of surfaces below) may be used to kill mould and whiten and remove the black stains that the mould produces. When the surface is visually clean, clean again with a fresh solution of bleach in order to kill any remaining non-visible mould spores. Allow all surfaces to dry thoroughly. In addition: Wash hands with soap and water after being in contact with floodwater or items that have been contaminated. Always wash hands before eating or preparing food. Wash all clothes worn during clean up activities in hot water and detergent. Wash them separately from uncontaminated clothes and linens. Use fans, air conditioners, heaters and dehumidifiers, if available, to help the drying process but bear in mind the advice below under ‘heating and ventilation’. Page 4/9 Inaccessible areas such as under floorboards may smell but are not necessarily a health hazard. Get further advice from the environmental health department if the smell persists. As property dries out, vacuum to remove loose material and dust on a regular basis. Soft furnishings, clothing, linens and bedding Bedding, clothing and other soft/fabric articles including children’s toys etc. should be decontaminated as below. Other soft furnishings that have been contaminated and cannot be put in a washing machine will have to be professionally cleaned. If this is not possible, they may have to be disposed of. Wash all clothes worn during the cleanup in hot water and detergent. These clothes should be washed separately from uncontaminated clothes and linens. Hygienic cleaning of laundry Laundry can be made hygienically clean by: washing at 40-60°C with a bleach-based product (check ingredients on the package) washing at 60°C or above (using any product as the higher temperature kills germs). Washing at temperatures of 40°C or less with a non bleach product is considered to carry a risk of inadequate decontamination. Food preparation and storage Do not be tempted to salvage foodstuffs (including tins) as they may be contaminated with sewage and chemicals left from the floodwater. Discard any food which has been in contact with sewage or floodwater. If it is not possible to reach shops, eat canned food provided that the can has not been punctured, corroded or shows signs of leakage. Thoroughly clean and then disinfect the lid of the can with a solution of bleach to prevent contaminants from entering into the contents on opening. If the contents of the can have an unpleasant odour or colour or if the food looks mushy and the liquid cloudy, dispose of the can in a sealed plastic bag. NEVER taste the food from cans that show any signs of spoilage in order to avoid the risk of botulism poisoning. Frozen food that has been at room temperature for a few hours should be discarded. Put flood-damaged food in black plastic refuse sacks, seal and put out when your next refuse collection is due. Wash your hands before preparing food and before eating a meal or snack. Ensure all surfaces that food will come into contact with are made “hygienically clean” before use (see below for instructions on hygienic cleaning of surfaces). If work tops and other areas show signs of damage, avoid food contact with these areas. Ensure all surfaces where food will be stored are hygienically cleaned, including shelves in the refrigerator. All crockery, cutlery and cooking utensils (pots and pans) that come into contact with food MUST be “hygienically cleaned” before re-use. If an adequate supply of Page 5/9 hot water is available this can be done by detergent-based cleaning followed by thorough rinsing. If available as dishwasher can be used. Do not use untreated floodwater for food preparation. Advice on treatment of water is given below. Use boiled water which has then been allowed to cool to wash food which is eaten raw. It is safe to use unboiled tap water for cooking of food if it will be boiled during the cooking process. Water Follow the advice of the local water company regarding the safety of the water supply. If a water treatment works becomes flooded, alternative supplies are normally available but consumers may be advised to boil water before drinking or temporarily refrain from using water for domestic purposes. Contact the local water company if there is a noticeable change in water quality, such as discolouration or a change in taste or smell. If in doubt, boil all water intended for drinking or use bottled water. Ensure water taps are cleaned and disinfected and run water through them thoroughly before using them for the first time. If water is a private supply rather than mains, it is very important to check that it has not been affected by flood water. If the supply has been covered with flood water or changes colour or taste, boil or otherwise treat the water before drinking. If drinking water becomes contaminated Boil water, including all water for drinking, brushing teeth, washing food and making ice. If a source of power is not available, then water can be treated with chlorine or iodine. If the water is turbid it must be pre-treated before boiling or disinfection. Use a bleach solution to rinse water storage containers before reusing them after flooding. Continue to treat water until the supply has been tested and shown to be safe. Boiling water Bringing water to a rolling boil will kill pathogens effectively. A rolling boil is when the water is bubbling so hard that the bubbles keep coming up when the water is stirred. A holding period of 3-5 mins will ensure that water is safe, except in situations where contamination with spore-forming bacteria, fungal or protozoal cysts or hepatitis virus is suspected, in which case 10 mins is advised. Water from the hot tap is not suitable for drinking. Chemical disinfection of drinking water Where chlorine or iodine tablets are available, they should be used as directed by the manufacturer. Alternatively water should be disinfected with hypochlorite in the form of bleaching powder or hypochlorite solution for 30 mins. The final concentration of chlorine should be 0.5-1mgm/l available chlorine after 30 mins. The amount of chlorine needed depends mainly on the concentration of organic matter in the water and should ideally be determined for each situation using a test kit. If this is not available, a slight smell of chlorine is a crude indicator. For details on preparing chlorine solutions consult the following: Household Water Treatment and Safe Storage Following Emergencies and Disasters. http://www.who.int/household_water/resources/emergencies.pdf Page 6/9 For disinfection with iodine a concentration of 3.7 mg/l, contact time 10 mins, is required (6.3 mg/l if virucidal contamination is suspected). Pre-treatment of turbid water Turbid water should be filtered through a cotton cloth to remove any solid materials, treated with alum and bleaching powder, stored for at least 2h and then decanted or filtered through a clean cloth. For pre-treatment add 10g alum and 5g lime per 100l of turbid water. For further advice on treatment of water consult: Emergency treatment of drinking water at point-of-use. WHO technical note for emergencies No. 5 http://www.who.int/water_sanitation_health/hygiene/envsan/tn05/en/index.html . Water for infants Where the drinking water supply is either interrupted or contaminated, it is important to take precautions for formula-fed infants. In these circumstances there are three options for the use of water to make infant formula milk: For preference, use bowser or bottled water which has been boiled and allowed to cool. Then follow the manufacturer's instructions on making up the feed. Commercially ready made formula milk may be used as an alternative to powdered feeds made up with bowser water. If neither option 1 or 2 are possible because there is no energy to allow boiling, bottled water (table, spring or mineral water) can be used unboiled to prepare baby feeds, but the prepared feed should then be used immediately. Unboiled bowser water should not be used. Children Keep children and pets out of affected areas until clean-up has been completed. Wash children’s hands frequently – and always before meals. Wash flood water-contaminated toys with hot water and detergent. Some toys can be cleaned by being put inside pillow cases and into ordinary clothes washing machines. Gardens and play areas Do not let children or pets play on grassed or paved areas which have been flooded until the area has been cleaned. Remove any toilet waste from affected areas and bury On patio and other surfaces, the risk of spread of germs from residues of faecal material can be reduced by application of concentrated bleach solution*. Sunlight and soil will help destroy harmful bacteria and outdoor areas will be safe to use within a week or so after flooding. Page 7/9 Other health concerns Be aware of potential chemical hazards during flooding. Avoid contact with water and materials which may have been chemically contaminated. If the floodwater contained oil, petrol or diesel it should go away with the floodwater and silt. Any remaining oil, diesel or petrol contamination can be removed using a detergent solution and washing the surface down after initial cleaning has been carried out. Remember that petrol or diesel generators, dehumidifiers and pressure washers should never be used indoors without adequate ventilation. The exhaust gases contain carbon monoxide which can quickly build up to poisonous levels without proper ventilation. Electrical appliances, which have been in contact with floodwater, should not be switched on until a competent electrician has checked them. Further advice on these issues is available on the UK Health Protection Agency website (http://www.hpa.org.uk/flooding) or contact NHS Direct on 0845 4647 or visit their website http://www.nhsdirect.nhs.uk. Hygienic cleaning of surfaces Since flood water affecting the home or other property is quite likely to be contaminated with sewage, animal faeces, refuse etc., it is important that all surfaces are “hygienically cleaned” in order to get rid of germs (pathogenic bacteria, viruses and protozoa) as well as visible dirt. Hygienic cleaning of surfaces can be achieved in a number of ways according to the extent of the contamination and the facilities available: Hygiene cleaning using detergent (liquid or soap) and hot water. Detergent (laundry or dish detergent) or soap and hot water cleaning can be used to produce a hygienically clean surface provided that the surface is thoroughly rinsed using clean running water. Mechanical action using a cloth, sponge or brush to maximise removal of soil and microbes is an important part of the process. Removal of soil by wiping with a cloth without subsequent rinsing is not considered sufficient to achieve a surface that is hygienic. Use of a contaminated cloth can actually spread pathogenic organisms onto previously uncontaminated hands and hand and food contact surfaces. Hygienic cleaning using soap or detergent and a disinfectant product. This process should be used on large surfaces which cannot be rinsed or for situations where an adequate supply of running water is not available: o Surfaces should first be cleaned to remove the visible soil using a solution of detergent or soap. Using a clean cloth apply to the surface. Since disinfectants are inactivated to a greater or lesser extent by the presence of soil, soiled surfaces, particularly heavily soiled surfaces MUST be cleaned before application of a disinfectant. o If the surface is only “superficially” dirty, it may be hygienically cleaned using a combined disinfectant/cleaner. The solution should be applied with a clean cloth or via a spray bottle and the surface then wiped. If necessary repeat the process until the surface appears visibly clean. o Use a disinfectant or disinfectant/cleaners such as a bleach-based product*, which is active against all types of pathogens including bacteria, bacterial spores, viruses and protozoa. Consult the manufacturers instructions for information on the “spectrum of action”, and method of use (dilution, contact time etc). Page 8/9 * Use a solution of bleach, diluted to 0.5% or 5000ppm available chlorine. Household bleach (both thick and thin bleach) typically contains 4.5 to 5.0% (45,000-50,000 ppm) available chlorine. In situations where concentrated bleach is required a solution containing not less than 4.5% available chlorine should be used. Bleach/cleaner formulations (e.g. sprays) are formulated to be used “neat” (i.e. without dilution). It is always advisable however to check the label as concentrations and directions for use can vary from one formulation to another. For more details on choosing the appropriate disinfectant, consult the IFH information sheet “Cleaning and disinfection: Chemical Disinfectants Explained” Other sources of Information. Further general advice in relation to flooding is available on the Health Protection Agency’s website at http://www.hpa.org.uk/flooding. Flooding – advice for the public. http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1317140405287 or contact NHS Direct on 0845 4647 or visit their website http://www.nhsdirect.nhs.uk Flood health advice http://www.nhsdirect.nhs.uk/articles/article.aspx?articleId=22 84. Advice for clean-up after hurricanes and floods from Center for Disease Control and Prevention (CDC), Atlanta, USA. http://www.bt.cdc.gov/disasters/floods/ IFH guidelines and training resources on home hygiene: Guidelines for prevention of infection and cross infection the domestic environment. International Scientific Forum on Home Hygiene. Available from: http://www.ifh-homehygiene.com/best-practice-care-guideline/guidelinesprevention-infection-and-cross-infection-domestic Recommendations for suitable procedure for use in the domestic environment (2001). International Scientific Forum on Home Hygiene. http://www.ifhhomehygiene.org/best-practice-care-guideline/recommendations-suitableprocedure-use-domestic-environment-2001 Home hygiene - prevention of infection at home: a training resource for carers and their trainers. (2003) International Scientific Forum on Home Hygiene. Available from: http://www.ifh-homehygiene.com/best-practice-training/homehygiene-%E2%80%93-prevention-infection-home-training-resource-carersand-their These give comprehensive guidelines on how, when and where, hygiene should be applied in the home to prevent the spread of infectious disease. This resource was last updated February 2014 Page 9/9