Break Bone Fever
DENS1 Dengue NS1 Ag, S
DNAGI Dengue Ag Interpretation
Aiding in the diagnosis of dengue virus
Results should be used in conjunction with clinical presentation and exposure history.
Though uncommon, false-positive nonstructural protein 1 (NS1) results may occur in individuals with active infection due to other flaviviruses, including West Nile virus and yellow fever virus.
Negative NS1 antigen results may occur if the specimen was collected greater than 7 days following symptom onset. Serologic testing for the presence of IgM and IgG antibodies to dengue virus is recommended in such cases.
Dengue virus (DV) is a globally distributed flavivirus with 4 distinct serotypes (DV-1, -2, -3, -4) and is primarily transmitted by the Aedes aegypti mosquito, found throughout the tropical and subtropical regions of over 100 countries. DV poses a significant worldwide public health threat with approximately 2.5 to 3 billion people residing in DV endemic areas, among whom 100 to 200 million individuals will be infected, and approximately 30,000 patients will succumb to the disease, annually.
Following dengue infection, the incubation period varies from 3 to 7 days, and while some infections remain asymptomatic, the majority of individuals will develop classic dengue fever. Symptomatic patients become acutely febrile and present with severe musculoskeletal pain, headache, retro-orbital pain, and a transient macular rash, most often observed in children. Fever defervescence signals disease resolution in most individuals. However, children and young adults remain at increased risk for progression to dengue hemorrhagic fever and dengue shock syndrome, particularly during repeat infection with a new DV serotype.
Detection of the DV nonstructural protein 1 (NS1) has emerged as an alternative biomarker to both serologic and molecular based techniques for diagnosis of acute DV infection. NS1 antigenemia is detectable within 24 hours and up to 9 days following symptoms onset. This overlaps with the DV viremic phase and NS1 is often detectable prior to IgM seroconversion. Concurrent evaluation for the NS1 antigen alongside testing for IgM- and IgG-class antibodies to DV (DENGM / Dengue Virus Antibody, IgG and IgM, Serum) provides optimal diagnostic potential for both early and late dengue disease.
Reference values apply to all ages.
The presence of dengue nonstructural protein 1 (NS1) antigen is consistent with acute-phase infection with dengue virus.
The NS1 antigen is typically detectable within 1 to 2 days following infection and up to 9 days following symptom onset.
NS1 antigen may also be detectable during secondary dengue virus infection, but for a shorter duration of time (1-4 days following symptom onset).
The absence of dengue NS1 antigen is consistent with the lack of acute-phase infection.
The NS1 antigen may be negative if specimen is collected immediately following dengue virus infection (<24-48 hours) and is rarely detectable following 9 to 10 days of symptoms.