C. diff and dengue tests cleared by FDA

New tests that can assist with diagnosis of Clostridium difficile and dengue fever were recently cleared for marketing, the FDA announced.

The Cepheid Xpert C. difficile/Epi assay is designed to rapidly detect the toxin B gene associated with C. difficile infection. The test determines if C. difficile is in a patient's stool and whether it is the epidemic 027/NAP1/BI strain. The assay is automated and works on the Cepheid GeneXpert Dx System, which consists of an instrument that houses single-use disposable cartridges, a personal computer, and software that allows tests to be run and viewed quickly. The test is intended for use as an aid in diagnosis. The detection of the 027/NAP1/B1 strain is for epidemiological purposes only and should not be used to determine or monitor treatment, according to an FDA press release.

The DENV Detect IgM Capture ELISA test is the first test to help diagnose dengue fever or dengue hemorrhagic fever, reported an FDA press release. The test detects antibodies to dengue virus in blood samples from patients who have signs and symptoms of dengue and will be available for use in clinical laboratories. Diagnostic testing for dengue is complicated by the fact that an IgM antibody response to the dengue virus infection is not detectable until 3 to 5 days after the onset of fever, so a test result can be negative even though a person has dengue. Most reported dengue cases in the continental U.S. occur in people returning from Latin America, the Caribbean and Southeast Asia.