Objective Clostridium difficile infection (CDI) is the major cause of antibiotic-associated diarrhea in hospital inpatients. Rapid testing for the toxins in stool specimens is inconclusive due to its low sensitivity. Therefore, a two-step method is recommended as the most appropriate approach. The purpose of the present study was to evaluate the differences in the disease severity score between the patients who were glutamate dehydrogenase (GDH)-positive/enzyme immunoassays (EIA) toxin-positive (group A) and those who were GDH-positive/EIA toxin-negative, but who were nonetheless finally confirmed to be toxin-positive by toxigenic culture testing (group B).
Methods A rapid detection EIA for GDH and toxin A/B were simultaneously performed for initial screening. Subsequently, the toxin production by bacterial colonies in culture was retested with the same rapid test kit when necessitated by an equivocal result of the initial screening.
Results A total of 334 fecal specimens were evaluated. Group A consisted of 25 specimens (from 16 patients) and group B consisted of 27 specimens (from 12 patients). The severity score (based on a number of factors, including age, body temperature, serum albumin level and white cell count) of group A and B was 2.2±0.7 and 1.4±0.5, respectively (p=0.002).
Conclusion The cases of CDI in which the toxins were detected by the initial screening test were more severe than those where the toxins were not detected at the initial screening but were identified by the toxigenic culture. In addition, the most significant factors affecting the severity score were an older age and a lower serum albumin level.