Explanation

Clostridioides (Clostridium) difficile (feces): what is measured?

Clostridioides difficile, previously called Clostridium difficile, is a bacterium that lives in the gut of some healthy people. When antibiotics are used, the bacterium can take over and make toxins that inflame the large intestine. The laboratory looks for the bacterium or one of its proteins (GDH) and for the toxins or the genes for them, with a rapid test or a PCR. Only a bacterium that makes toxins can make you ill.

What can it detect?

C. difficile infection: diarrhea caused by toxins, often during or up to 3 months after antibiotics
Carriage without symptoms, which according to the LCI guideline (RIVM) occurs in 3 to 15 in 100 healthy adults

Result

What does the result mean?

Positive result

A positive result means that the bacterium or its toxins have been found. With diarrhea, especially during or after antibiotics, this may fit a C. difficile infection; this ranges from mild diarrhea to severe inflammation of the bowel with fever and abdominal pain. Without diarrhea, a positive result fits carriage, and according to the LCI guideline (RIVM) that is no reason for treatment. In children younger than 2 years, carriage is very common: it occurs in up to 30 in 100.

Negative result

A negative result means that the pathogen was not found in this stool sample. Some pathogens are shed irregularly, and shortly after infection the pathogen sometimes cannot be detected yet; so an infection is not always ruled out. According to Thuisarts.nl, diarrhea is usually caused by stomach flu; diarrhea that lasts longer than 2 weeks can also have other causes, such as medicines, not tolerating lactose well or an irritable bowel.

After an abnormal result

In an infection, according to the LCI guideline (RIVM), stopping the antibiotics, if possible, is the most important measure; with moderate to severe symptoms, the doctor prescribes an antibiotic that works specifically against C. difficile. Anti-diarrhea medicines such as loperamide are not recommended. A C. difficile infection is not notifiable for individual cases; only multiple cases in an institution must be reported by the institution to the GGD (municipal public health service).

Reliability

How reliable is the test?

Testing the stool for pathogens that cause intestinal infections is routine testing in Dutch laboratories. According to the LCI guidelines (RIVM), a PCR is preferred over microscopy or culture for most pathogens, because it is more sensitive; a culture is sometimes still needed afterwards to type the bacterium or test its sensitivity to antibiotics. According to Thuisarts.nl, stool testing for diarrhea is mainly useful if you are very ill or if the diarrhea lasts longer than 2 weeks and does not get better; short-term diarrhea is usually caused by stomach flu and usually clears up on its own.

What can affect the result?

Parasites and worm eggs are shed irregularly; one sample can miss an infection, which is why laboratories sometimes ask for samples from several days.
Shortly after infection, the pathogen may not yet be detectable in the stool.
The longer the sample is in transit, the smaller the chance of a positive culture.
A PCR can also find genetic material from a pathogen that is no longer alive or from an infection that has already passed.

Who it is for

Who is the test useful for?

Useful for

According to the LCI guideline (RIVM), testing is useful with diarrhea during or up to 3 months after antibiotic use, and in older people or people with a serious illness who have diarrhea without another explanation. Without diarrhea, on a solid stool sample or in children younger than 2 years, a positive result says little, because it is then often due to carriage.

How common is it?

According to the LCI guideline (RIVM), 3 to 15 in 100 healthy adults carry C. difficile without symptoms, and about 35 in 100 hospital patients. In Dutch hospitals, there are about 15 infections per 10,000 admissions. A growing share of infections, 20 to 30 in 100, starts outside the hospital.

LCI guideline (RIVM) on Clostridioides difficile

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