Clostridium difficile infection is the most important cause of hospital-acquired diarrhoea. Clostridium difficile is an anaerobic bacterium that is present in the gut of up to 3% of healthy adults and 66% of infants. However, Clostridium difficile rarely causes problems in children or healthy adults, as it is kept in check by the normal bacterial population of the intestine.
When certain antibiotics disturb the balance of bacteria in the gut, Clostridium difficile can multiply rapidly and produce toxins which cause illness.
Clostridium difficile infection ranges from mild to severe diarrhoea to, more unusually, severe inflammation of the bowel (known as pseudomembranous colitis). People who have been treated with broad spectrum antibiotics (those that affect a wide range of bacteria), people with serious underlying illnesses and the elderly are at greatest risk – over 80% of Clostridium difficile infections reported are in people aged over 65 years.
Clostridium difficile infection is usually spread on the hands of healthcare staff and other people who come into contact with infected patients or with environmental surfaces (e.g. floors, bedpans, toilets) contaminated with the bacteria or its spores. Spores are produced when Clostridium difficile bacteria encounter unfavourable conditions, such as being outside the body. They are very hardy and can survive on clothes and environmental surfaces for long periods.
Public Health England - PHE (formerly the Health Protection Agency) collects information on Clostridium difficile from a number of sources.