Immunoassay Approved for Detecting Dengue Fever Virus

An enzyme-linked immunosorbent assay (ELISA) is now available to test blood samples for the presence of antibodies to the dengue virus.

The ELISA test is designed for the qualitative detection of Immunoglobulin M (IgM) antibodies to dengue recombinant antigens (DENRA) in serum for the presumptive clinical laboratory diagnosis of dengue virus infection in patients with clinical symptoms consistent with dengue fever or dengue hemorrhagic fever.

The complete kit includes one 96 well strippable plate with all necessary reagents and controls. The ELISA is easy to use and accurate and performance was thoroughly evaluated in prospective studies and with clinically confirmed cases of dengue 1-4 serotypes. It was developed with a new generation of US Centers of Disease Control and Prevention (CDC; Atlanta, GA, USA), licensed recombinants expressed in mammalian cells. The accuracy was improved by monitoring background reactivity with Normal Cell Antigen and employs a simple, one-step ratio method of interpretation.

Diagnostic testing for dengue is complicated by the fact that an IgM antibody response to the dengue virus infection is not detectable until 3-5 days after the onset of fever, which can produce a negative test result even though a person has dengue. During this IgM negative window, the dengue virus is present in the bloodstream. The DENV Detect IgM Capture ELISA test is based on technology patented by the CDC and manufactured by Inbios Inc, (Seattle, WA, USA). This new test shows cross-reaction with other closely related viruses such as those that cause West Nile disease. However, in most patient testing situations found in the US, a positive test result in a patient with signs or symptoms consistent with dengue should be considered presumptive evidence of dengue.

This is the first in vitro assay for dengue, where the US Food and Drug Administration, (FDA; Silver Springs, MD, USA), reviewed data for the test via the "de novo" pathway, an alternative path to market for devices that are low to moderate risk and may not require premarket approval. Alberto Gutierrez, PhD, director of the Office of In Vitro Diagnostics Device Evaluation and Safety in FDA's Center for Devices and Radiological Health, said, "Cases of dengue fever or dengue hemorrhagic fever can be potentially fatal for people who do not recognize the symptoms. This test will now aid healthcare professionals in their effort to more effectively diagnose dengue."

Related Links:
US Centers of Disease Control and Prevention
Inbios Inc.
US Food and Drug Administration