Clostridium difficile toxin - faeces

Toxin detected by effect on cells in tissue culture or by EIA.

Detection of toxin confirms the diagnosis of Clostridium difficile associated diarrhoea.

The tissue culture technique, which detects toxin B, is still the most reliable method but is time consuming and is only used in a few laboratories.

EIA tests are more practical, although less sensitive. 

Growth of C. difficile on anaerobic culture supports the diagnosis but is less definitive than toxin detection.

The test is seldom useful in infants, as C. difficile and its toxin are commonly found in the faeces of healthy infants under 2 years of age.