People, pets and food are the main carriers of germs into the home. Once in, germs can get everywhere.
Find out where germs lurk in your home. It makes for uncomfortable reading and may prompt you to want to know more about preventing germs from spreading.
Kitchen sink squalor
Most people think of the toilet as the most contaminated part of the house, but in fact the kitchen sink typically contains 100,000 times more germs than a bathroom or lavatory.
Don't forget your toothbrush
When you flush, germs from the toilet bowl can travel as far as six feet, landing on the floor, the sink and your toothbrush. A study showed that significant quantities of microbes float around the bathroom for at least two hours after each flush. Always put the toilet lid down before flushing.
A used kitchen sponge can contain thousands of bacteria per square inch, including E. coli and salmonella. The sponge's moist micro-crevices are a trap for germs and are difficult to disinfect. Replace sponges regularly.
The average kitchen chopping board has around 200% more faecal bacteria on it than the average toilet seat. Hygiene experts advise you to use separate chopping boards for red meat, poultry, fish and vegetables.
Hands are the biggest spreaders of germs in the home. Studies show that hand washing lowers the transmission of diarrhoea and colds, and targeted disinfection at critical sites reduces the spread of infection in the home. Wash your hands frequently during the day with hot water and soap to prevent spreading germs. Wash them every time you've been to the toilet, and before and after preparing food.
While some germs cause disease, not all microbes are harmful. They are the foundation of the food chain that feeds all life on earth and we would not survive without them.
Bacteria can grow and divide every 20 minutes. One single bacterium can multiply into more than eight million cells in less than 24 hours.
Carpets are the largest reservoir of dust in the home. They contain hair and skin cells, food debris, dirt and insects. A home with floorboards is believed to have a tenth of the dust of one with wall-to-wall fitted carpets.
Handle with care
The greatest risk of infection in the bathroom comes from surfaces that are frequently touched by the hands, including the toilet flush handle and seat, taps and door handles.
Clothes, towels and linen can carry germs. Washing very soiled items at a high temperature reduces the risk of infection. Wash your hands after handling dirty laundry.
More than 50% of raw chicken contains the campylobacter bacteria, which causes more illness than salmonella in Britain. Cooking chicken until it reaches a temperature of 70C (158F) can help to ensure that it's safe to eat. You can test the temperature of food with a food thermometer.
Campylobacter is carried by about half of all dogs and cats, and can cause food poisoning in people. The bacteria are passed on when you stroke your pets. Always wash your hands after coming into contact with pets.
The bedroom is the perfect breeding ground for dust mites, which feed on dead skin. The average person sheds up to 10g (0.35oz) of dead skin a week and up to 18kg (40lb) in their lifetime.
About 40% of cases of food poisoning occur in the home, according to a European-wide study by the World Health Organization in 2003.
A swab of a handbag showed up to 10,000 bacteria per square inch. A third of bags tested positive for faecal bacteria. Bags come into contact with some very dirty places, including public transport, public toilets, and restaurant and bar floors.
Our shoes pick up all kinds of dirt when we're outdoors, including animal faeces. When we walk around in them at home, these germs get liberally spread around, settling into carpets and increasing the risk of infection. Hygiene experts advise taking your shoes off before you walk around the house.
Placing hot food in the fridge can lead to uneven cooling, which can cause food poisoning. It can take a long time for the temperature in the middle of the food to drop, which creates the perfect environment for bacteria to multiply.