Three-step diagnostic algorithm in diagnosing patients suspected of Clostridium difficile-associated diarrhea

Clostridium difficile is a predominant etiological agent of healthcare-associated infectious diarrhea. Immunoenzymatic tests for detecting toxins A/B from faecal samples are still used in routine diagnosis of Clostridium difficile-associated diseases in a number of healthcare centers in Poland. Recently, however, new diagnostic tests were introduced which allow for detecting toxigenic strains of C. difficile in a more effective and precise manner. It is of importance, especially in the light of hypervirulent strain occurrence.

The aim of the present paper was to evaluate the efficacy of three-step algorithm in the diagnosis of Clostridium difficile-associated diseases (CDAD), considering the occurrence of false negative test results for toxins while using exclusively immunoenzymatic tests.

In the present study, faecal samples collected from patients presenting diarrhea were tested. Immunoenzymatic tests were used for detecting glutamate dehydrogenase (GDH) and toxins A/B. Culture and RT-PCR were also employed.

Of 615 study participants, toxigenic strains GDH (+) TOX (+) were identified in 108 patients while for 67 patients, test results remained unspecified GDH (+) TOX (-). Further analysis of unspecified samples revealed 32 patients infected with toxigenic strains, i.e. 22.9% of all positive test results (n=140).

Three-step diagnostic algorithm is an effective and reliable tool for diagnosing C.difficile- associated diseases.