C.difficile (C.diff) - Causes of Clostridium difficile infection

Clostridium difficile are anaerobic bacteria. This means they do not need oxygen to survive and multiply. They therefore survive well in the colon (bowel), where there is very little oxygen.

C. difficile does not usually affect healthy children and adults. This is because the bacteria normally present in the healthy bowel 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) that cause illness. At this point, a person is said to have a Clostridium difficile infection.

Spread of infection

Once C. difficile bacteria start to produce toxins, the bacteria can spread easily. This is because the bacteria are now producing spores (a much more resistant form of the cell) that leave the body in an infected person's diarrhoea.

The spores are resistant to conditions outside the body and can contaminate toilets, bedclothes, skin and clothing.

The spores of 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, for example while making the bed. They can survive for a long time outside the body unless they are removed by very thorough cleaning.

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), such as amoxicillin and cefalexin
have had to stay in a healthcare setting for a long time
are over 65 years old
have a serious underlying illness or condition
have a weakened immune system, which can be because of a condition such as diabetes or a side effect of a treatment such as chemotherapy
have had surgery on the digestive system

Previously, the majority of infections occurred in places where many people take antibiotics and are in close contact with each other, such as hospitals and care homes.

Control measures have been effectively implemented to dramatically reduce the number of infections in healthcare settings. A number of precautions can be taken to help reduce the spread of infection.