Clostridium Difficile

What is Clostridium difficile infection?

Clostridium difficile is a bacterium (germ). It lives harmlessly in the gut of many people. About 3 in 100 healthy adults and as many as 7 in 10 healthy babies have a number of Clostridium difficile bacteria living in their gut. The number of Clostridium difficile bacteria that live in the gut of healthy people is kept in check by all the other harmless bacteria that live in the gut. So, in other words, some of us normally have small numbers of Clostridium difficile bacteria living in our guts, which do no harm.

Clostridium difficile produces spores (like 'seeds') which are very hardy and resistant to high temperatures. Spores are passed out with the faeces (stools) of people who have Clostridium difficile in their gut. Spores can persist in the environment (for example, on clothes, bedding, etc) for several months or years. The spores may get onto food, and into the mouth and gut of some people. Spores that get into a human gut develop into mature bacteria. So, this is how some people end up with Clostridium difficile living harmlessly in their gut.

However, if the number of Clostridium difficile bacteria increases greatly in the gut, then it can cause problems. The commonest reason why this occurs is due to taking antibiotics.

Antibiotics are the main cause Clostridium difficile infection
If you take antibiotics for another reason, say for a urine infection, then the antibiotic will also kill many of the harmless bacteria that live in your gut. Clostridium difficile bacteria are not killed by many types of antibiotic. If the other harmless bacteria are killed, then this allows Clostridium difficile to multiply to greater numbers than it would normally do.

Therefore, if you take certain antibiotics and if you have any Clostridium difficile bacteria in your gut, the bacteria may thrive and cause an infection. This is a problem that may occur with taking many of the commonly used antibiotics.

How serious is the infection that can develop?

Clostridium difficile bacteria make toxins (poisons) that can cause inflammation and damage to the inside lining of the lower gut (the colon, also known as the large bowel). There are different strains of Clostridium difficile, and some can cause a more serious illness than others. The severity of the infection and illness can vary greatly.

Many cases are mild
Many people develop mild or moderate watery diarrhoea. There may also be some crampy abdominal pains, nausea (feeling sick) and fever. This is similar to the symptoms that occur with many other mild or moderate bouts of gastroenteritis (gut infection). Symptoms may last from a few days to several weeks, but often clear away without any specific treatment.

Pseudomembranous colitis
This occurs in some cases and is more serious. Colitis means inflammation of the colon. Pseudomembranous means that if you were to look inside the colon, you would see membrane-like patches on the inside lining of the colon. This can cause bloody diarrhoea, abdominal pain, fever, and make you very unwell. In some cases it becomes severe and life-threatening ('fulminant colitis') and the colon may perforate (rupture).

Who gets Clostridium difficile infection?

Anyone who takes a course of many types of antibiotic is at risk of developing Clostridium difficile infection. In most cases, the symptoms start within a few days of starting the antibiotic. However, in some cases symptoms develop up to 10 weeks after finishing a course of antibiotics. As a rule, the longer the course of the antibiotic, the greater the risk of developing Clostridium difficile infection.

However, most cases occur in people who are in hospital, or who have recently been in hospital. This is because Clostridium difficile bacteria and spores are more likely to be found in hospitals. People in hospital are therefore more likely to become infected. Also, people in hospital are more likely to have been given antibiotics. Clostridium difficile infection is often spread from one patient to another in hospital. This often occurs by spores getting on the hands of healthcare staff who come into contact with infected people or objects contaminated with bacteria or spores. For example, contaminated bedpans, toilets, bedding, etc.

The exact number of cases that occur in hospital patients is difficult to determine. However, it is common. About 3 in 10 people who become infected develop symptoms. Commonly this is just a mild or moderate bout of diarrhoea, but it sometimes develops into pseudomembranous colitis.

Clostridium difficile infection is more common in older people. Over 8 in 10 cases occur in people over the age of 65. This is partly because older people are more commonly in hospital. Also, older people seem to be more prone to this infection. It is rarely a problem with children. As a rule, the longer the stay in hospital and the older your are, the greater your risk of developing Clostridium difficile infection.

How is Clostridium difficile infection diagnosed?

As a general guide, the diagnosis of Clostridium difficile infection should be suspected in:

• anyone who develops diarrhoea who has had antibiotics within the previous two months, and/or
• when diarrhoea develops during a hospital stay, or within a few weeks of coming out of hospital.

Obviously, diarrhoea is often due to other causes, but Clostridium difficile should be considered as a possibility in the above situations. A stool (faeces) sample can be tested in the lab to confirm the diagnosis.

What is the treatment for Clostridium difficile infection?

The decision to treat Clostridium difficile infection, and the type of treatment, depends on the severity of the illness. No treatment is needed if you have no symptoms but are known to 'carry' the bacteria in your gut. If symptoms develop:

• If at all possible, the antibiotic that has caused the problem should be stopped. This will allow the normal harmless bacteria to thrive again in the gut. The 'overgrowth' of Clostridium difficile should then reduce and symptoms often ease.
• Stopping the antibiotic may be the only treatment necessary if you just have mild or moderate diarrhoea. In fact, many people will have stopped the antibiotic anyway as the course of antibiotics may have just been for a few days.
• People with more severe diarrhoea or colitis will normally be given an antibiotic that is known to kill Clostridium difficile. This is usually vancomycin or metronidazole. Symptoms then usually ease within 2-3 days. In severe cases, prompt treatment with vancomycin or metronidazole may ease any colitis and prevent perforation of the colon.
• In the small number of cases that progress into fulminant colitis, surgery may be needed, especially if the colon perforates.

What is the outlook (prognosis)?

Most people with Clostridium difficile infection recover, even without any treatment. However, the diarrhoea can be unpleasant and in some cases can last for several weeks. If needed, treatment with metronidazole or vancomycin gives a good chance of clearing the infection quickly.

Severe colitis due to Clostridium difficile infection occurs in some cases. This accounts for most of the serious complications such as perforation of the colon, and death. Most people who die of Clostridium difficile infection are elderly people who are frail or ill with other things, and who develop the infection during a hospital stay.

Can Clostridium difficile infection be prevented?

Strict personal hygiene such as washing hands after going to the toilet can reduce the spread of this and other infections. Good cleaning practices and strict hygiene measures in hospitals helps to prevent contamination of equipment and personnel with bacteria and spores.

References

• Health Protection Agency Information about Clostridium difficile. Various dates. Website accessed January 2007
• Craig A Gronczewski and Jonathan P Katz Clostridium Difficile Colitis Emedicine Article dated August 10th 2006
• Susan M. Poutanen and Andrew E. Simor Clostridium difficile-associated diarrhea in adults CMAJ July 6, 2004; 171 (1).

© EMIS and PIP 2007   Updated: February 2007