Beware of common household germs

Micro-organisms are vital to humans and the environment, but some are harmful to us. These are commonly referred to as germs. "Germ" is a catch-all term for these invisible organisms – mainly bacteria, fungi and viruses – which cause disease.

To protect you and your family from germs, hygiene experts say you should focus your cleaning efforts on germ hotspots in the home, such as cleaning cloths, sponges and chopping boards. Find out how to prevent germs from spreading.

Germs mainly enter the home on people, food and pets. Once they're in, they can spread from person to person, or from person to surface and back again (cross-contamination).

Common germs found in the home are:

• MRSA (meticillin-resistant Staphylococcus aureus): this is a strain of the common Staphylococcus aureus bacteria. It's resistant to many antibiotics, making the infections it causes difficult to treat. Washing hands with soap and hot water is the most effective way to prevent it spreading.
• E. coli 0157: a more dangerous strain of the common E. coli bacterium, usually found in the gut of all healthy humans. It can cause severe intestinal illness. Pay careful attention to hygiene around food and around the toilet, especially if someone has diarrhoea.
• Norovirus: also known as the winter vomiting bug. Norovirus is the most common cause of infectious gastroenteritis in England. Wash your hands thoroughly with soap and hot water after preparing food and before eating, and especially after using the toilet.
• Clostridium difficile: also known as C. diff. This is a bacterium found in the gut of less than 5% of healthy adults. It does not cause any harm to healthy people because of the balance of "good" bacteria in the gut. It's common in the intestine of babies and infants, but does not cause disease because its poisons do not damage their immature intestinal cells. A C. diff infection can cause diarrhoea, which can range from a mild disturbance to a very severe illness with ulceration and bleeding from the colon and, at worst, perforation of the intestine, leading to peritonitis. This can be fatal. Make sure hands are thoroughly washed before and after preparing food, and especially after going to the toilet.

Many of these germs are caught in the home. According to a World Health Organization report in 2003, about 40% of reported food-related outbreaks of infection in Europe occur in the home.

Microbiologist Professor Sally Bloomfield, of the International Scientific Forum on Home Hygiene (IFH), says that home hygiene does not mean being obsessive about deep cleaning our homes. "Our routine daily or weekly cleaning habits actually have little effect in reducing our exposure to harmful microbes."

She says that most germs are spread on the hands and surfaces that come into contact with hands, cleaning cloths and utensils.

Bloomfield says focusing on germ hotspots is more effective at preventing germs spreading than a "once-weekly deep clean".