Clostridioides difficile infection (CDI) is often confirmed through toxin testing, yet toxin tests alone may not be sufficient for diagnosing and guiding treatment decisions for patients with CDI.
Dr David Lyerly
"The presence of a toxigenic strain does not always equal disease," said David Lyerly, PhD, during a session on C difficile toxin testing at the Peggy Lillis Foundation 2022 National C. diff Advocacy Summit.
Lyerly, the chief science officer at Techlab, explained that exotoxins A and B are produced by specific strains of C difficile and are involved in infections, but some patients who test positive for these toxins by polymerase chain reaction or other tests do not have CDI or they are not appropriate candidates for CDI treatment.
Several studies conducted during the past decade, however, support the importance of toxin detection. Some research has suggested that toxin-positive patients tend to have more clinically severe disease than those who test negative, he noted.
Although its use is limited when it is used alone, toxin testing is needed to confirm a CDI diagnosis and to ensure antibiotic stewardship, Lyerly said.
He suggested that in addition to toxin testing, there is a need for molecular measures and other improved diagnostics to identify candidates most likely to benefit from CDI treatment.
