The toxin-producing bacterium Clostridioides difficile is responsible for a large proportion of diarrhoeal diseases after antibiotic administration. It is estimated that Clostridioides difficile infections, most of which are preventable, cause additional annual costs of 3 billion euros in European hospitals.

Worldwide

Clostridioides difficile are found in the intestinal tract in humans and animals, but can also be isolated in the environment.

Often patients are already carriers of the pathogen. In most cases, hygiene deficiencies in the hospital are responsible for the transmission to patients.

Due to the severity of the symptoms, different courses are described: Antibiotic-associated diarrhea and antibiotic-associated colitis (AAC) with fever, intestinal cramps and severe, sometimes bloody, diarrhea.

Medication, in rare cases, surgical partial colon removal may be necessary.

In 2023, 136 submissions were made to the Austrian reference centre for Clostridioides difficile . At the same time, 511 cases of severe C. difficile infections were reported to the epidemiological reporting system (EMS). Since 18 January 2010, severe Clostridioides difficile infections(CDI) have been subject to mandatory reporting under the Epidemics Act.

Clostridioides difficile belongs to the group of gram-positive anaerobic spore-formers. They are mainly found in the intestinal tract in humans and animals, but can also be isolated in the environment. The spores (bacterial permanent forms of the pathogen) are extremely environmentally resistant and protect the pathogen from temperatures above 100 °C and also from numerous disinfectants.

The toxin-producing C. difficileis responsible for a large proportion of diarrhoeal diseases following antibiotic administration and is subject to compulsory notification in the event of a severe course according to the Epidemic Law. Due to the emergence of the hypervirulent C difficile strain PCR ribotype 027 (NAP type 1) in North America and Europe, this pathogen has become the focus of interest. According to current estimates, the mostly preventable C. difficile infections in European hospitals cause annual additional costs of 3 billion euros.

Often the patient is already a carrier of the pathogen. Antibiotic administration leads to a shift in the ecological balance in the intestinal flora, which favours C. difficile. In other cases, however, transmission of the spores is the cause of the disease. In most cases, hygiene deficiencies in the hospital are responsible for transmission to patients, which can also lead to epidemics. Toxin-forming C. difficile is responsible for a large proportion of diarrhoeal diseases after antibiotic administration.

Due to the severity of the symptoms, different courses are described:

• The mildest course is antibiotic-associated diarrhea (AAD), which usually resolves after the end of antibiotic therapy.
• More problematic is antibiotic-associated colitis (AAC), which in the worst case can be fatal if toxic megacolon occurs. AAC is associated with fever, intestinal cramps, and severe, sometimes bloody, diarrhea.

Not all C. difficile isolates have genes for toxin production. Generally, toxin-A and toxin-B are responsible for AAD and AAC. Little is known about the effect of the binary toxin produced by only 6-10% of all isolates (=microorganisms obtained from a sample).

Therapy

Metronidazole is the drug of choice, vancomycin and teicoplanin are usually only administered if therapy fails. In rare cases, for example in toxic megacolon (=acute dilatation of the colon), surgical partial colon removal may be indicated. At present, the pathogen is usually only detected in the stool of patients by means of rapid toxin tests. However, due to the importance of also detecting outbreaks, a cultural cultivation test should always be performed as well.

In Austria, the rate of C. difficile infections in hospitals has increased threefold since 2002. In comparison, the rate in Germany increased sixfold in the same period. These figures illustrate the need for nationwide surveillance and typing of the pathogen in order to be able to react quickly and efficiently to changes and the emergence of hypervirulent pathogens.

Since 18 January 2010, severe C. difficile infections(CDI) have been subject to compulsory notification under the Epidemics Act. A severe course exists if:

• the CDI requires intensive medical treatment
• the C. difficile infection leads to complications that require surgical intervention
• the CDI takes a lethal course