Clostridium difficile (C. difficile) is an anaerobic bacterium. This means it does not need oxygen to survive and multiply. Therefore, it usually survives well in the large intestine (bowel), where there is very little oxygen.
Infection
C. difficile does not usually affect healthy children and adults. This is because the healthy 'good' bacteria in the intestine keep it under control. However, some antibiotics can interfere with the healthy balance of bacteria. When this happens, C. difficile bacteria can multiply and produce toxins (poisons), which cause illness. At this point, a person is said to be infected with C. difficile.
Spread
Once C. difficile bacteria start to produce toxins, the bacteria can spread easily. This is because the bacteria produce spores (a form of cell that is highly resistant to chemicals), which leave the body in an infected person's diarrhoea. The spores are resistant to the conditions outside the body and can contaminate their surroundings, such as toilets, bedclothes, skin and clothing.
The spores or bacteria are spread by the hands of healthcare staff and other people who come into contact with infected patients or contaminated surfaces.
The spores can also be spread through the air (during bed making, for example). They can survive for a long time outside the body unless they are destroyed through very thorough cleaning.
Who is most at risk?
People most vulnerable to a C. difficile infection are those who:
- have been treated with broad-spectrum antibiotics (antibiotics that can treat different types of bacteria)
- have had to stay for a long time in a healthcare setting, such as a hospital
- are over 65 years old
- have a serious underlying illness or condition
- have a weakened immune system
- have had many enemas (injections of liquid into the back passage) or gut surgery
Most infections occur in places where many people take antibiotics and are in close contact with each other, such as hospitals and nursing homes. A number of precautions can be taken to help reduce the spread of infection (see Preventing C. difficile infection for more information).
