Contrasting Results from Two Commercial Kits Testing for the Presence of Clostridium perfringens Enterotoxin in Feces from Norovirus-Infected Human Patients.

Background: Detection of Clostridium perfringens enterotoxin (CPE) is critical for disease surveillance; however, commercial testing kits produce contrasting results. Methods: We examined the cause of the differing results from a reversed passive latex agglutination (RPLA) assay (PET-RPLA Toxin Detection Kit) and an enzyme-linked immunosorbent assay (C. perfringens Enterotoxin ELISA Kit) using 73 human norovirus-positive fecal samples from gastroenteritis patients across 22 episodes in Japan. Results: CPE was detected in 39/73 samples using the RPLA method; however, ELISA-based examination of 10 RPLA-positive samples produced negative results. Moreover, cpe was not detected in any of the RPLA-positive (n = 32) or -negative (n = 5) samples, and C. perfringens was only isolated from one RPLA-positive sample. Conclusions: An ELISA-based testing approach may be more reliable than RPLA assays for CPE detection from human fecal samples. These findings may also be applicable to the detection of other foodborne diseases.