NS1 antigen test (nonstructural protein 1), is a test for dengue, introduced in 2006. It allows rapid detection on the first day of fever, before antibodies appear some 5 or more days later.
An aid in the diagnosis of dengue virus infection
Positive:
The presence of dengue nonstructural protein 1 (NS1) antigen is consistent with acute-phase infection with dengue virus. Negative:
The absence of dengue NS1 antigen is consistent with the lack of acute-phase infection.
