Clostridium difficile infection (CDI) - including symptoms, treatment and prevention
Clostridium difficile infection (CDI) is a disease of the large intestine caused by toxins produced by the spore forming bacterium Clostridium difficile. Around 5 to 10% of healthy people and many children under 2 years of age have these bacteria in the bowel without causing any symptoms. The bacteria are also found in animals such as pigs, horses and cattle.
How Clostridium difficile is spread
The main source of transmission is patients with symptomatic infection. These people shed large numbers of C. difficile spores and bacteria in the faeces, resulting in widespread contamination of their skin, bed linen and nearby environmental surfaces. The spores are resistant to drying and the usual chemical cleaning agents, and can therefore remain in the environment for weeks or months. Spores can then be picked up on the hands of patients and healthcare workers.
Risk factors for CDI include
- recent antibiotic use
- long hospital stay
- older age
- cancer chemotherapy and other immune suppression
- other serious underlying illness.
Since 2000, strains of C. difficile associated with outbreaks of infection (epidemic) and with more severe infection (hypervirulent) have been recognised. One strain appears to be easily and quickly transmitted from person-to-person and has been responsible for large outbreaks of infection in the United States of America (USA) and Europe. There are also increasing reports of cases in community settings with no history of recent antibiotic use.
Signs and symptoms
Mild, self-limiting symptoms can include:
- diarrhoea (watery or sometimes bloody)
- loss of appetite
- abdominal pain
A serious form of the disease, known as pseudomembranous colitis (severe inflammation of the lining of the gut) has a high death rate if not recognised early and treated appropriately.
The trigger for symptoms is usually a disturbance of the normal bacteria in the gut during antibiotic treatment. This allows C. difficile to colonise (become established in) and multiply in the gut and produce toxins that attack the lining of the gut wall.
Diagnosis is made by laboratory testing of faeces from people with diarrhoea. The usual test for C. difficile toxin does not distinguish between strains. More specialised tests (PCR or polymerase chain reaction tests in a pathology laboratory) are required to detect the epidemic strains thought to be responsible for more severe disease.
(time between becoming infected and developing symptoms)
Average of 2 to 3 days
(time during which an infected person can infect others)
A person with diarrhoea from C. difficile infection is infectious while symptoms persist. C. difficile spores can survive in the environment for weeks or months.
CDI can be difficult to treat and has a high relapse rate. People with CDI are usually treated with antibiotics (metronidazole, or oral vancomycin in more severe disease and recurrent infections). There is no proof that probiotics (such as the natural bacteria in yoghurt) or faecal enemas are effective for treatment.
- The most important measure to prevent the emergence of new strains of C. difficile in Australia is reducing the unnecessary use of antibiotics, especially those known to be closely linked to CDI.
- Exclude people with C difficile infection from childcare, preschool, school and work until there has been no diarrhoea for 24 hours. If working as a food handler in a food business, the exclusion period should be until there has been no diarrhoea and/or vomiting for 48 hours.
If a person with C. difficile infection is being managed at home:
- practise good hand hygiene with soap and water
- clean contaminated surfaces with a chemical disinfectant that can kill the C. difficile spores, for example household bleach.
In a residential care facility or hospital
If a person with Clostridium difficile infection is being managed in a residential care facility or hospital, the Australian Guidelines for the Prevention and Control of Infection in Healthcare (2010) recommend:
- good hand hygiene by staff and residents
- standard and contact precautions, particularly use of gloves
- appropriate use of personal protective equipment
- disinfection of equipment shared between residents or patients
- environmental hygiene with a chemical disinfectant that can kill the C. difficile spores (for example, detergent and water, followed by sodium hypochlorite 0.1% - a 1 in 50 dilution of household bleach)
- placing residents or patients with infection in rooms away from other residents or patients
- minimising resident or patient transfer or transport.
While there is some controversy regarding the use of alcohol hand rubs for spore-forming organisms, recent consensus is that the use of gloves, as part of contact precautions, should prevent the contamination of hands with spores, and alcohol-based hand rubs can still be used after removal of the gloves. However, if there has been any unprotected exposure (for example, touching the patient or their environment without wearing gloves or direct soiling of the hands) then thorough washing with soap and water should be performed.