Dengue Virus Testing

Dengue virus is a flavivirus transmitted to humans by Aedes mosquitoes. An estimated 50-100 million infections occur annually throughout the world. Dengue virus primarily affects persons living in or traveling to tropical areas. Nearly all dengue cases reported in the 48 continental states were acquired elsewhere by travelers or immigrants, with sporadic cases reported along the southern U.S. border (eg, in Arizona, Texas, Florida) and in Hawaii.

Symptoms of dengue infection can range from mild febrile illness to bleeding (dengue hemorrhagic fever) or hypotension (dengue shock syndrome) with potentially high mortality. It is important to diagnose dengue promptly, since other tropical infections can produce similar patterns of illness and may require different treatment.

Dengue nonstructural protein 1 (NS1) is an antigen produced in abundance by the replicating dengue virus as early as the first day of symptoms and as late as day 18 of symptoms.1 NS1 can be detected in the blood sooner than IgM, which cannot be reliably detected until days 6 to 10.1

Detection of NS1 antigen allows an accurate diagnosis of current infection within the first week of illness (ie, during the febrile phase). Detection of IgM antibody, on the other hand, indicates possible current infection or recent infection (within the past 2 to 3 months).1 An acute and convalescent specimen is thus required to diagnose current infection. Additionally, the NS1 antigen is specific to dengue, whereas the antibody may cross react with other flaviviruses such as West Nile virus, St. Louis and Japanese encephalitis viruses, and yellow fever virus.¹

Specimen collection requirements are the same as for the antibody test (ie, 1 mL of room-temperature serum). However, only 1 specimen collection is needed; ie, acute and convalescent specimens are not needed to make the diagnosis.

Yes. The Dengue Fever Antibodies (IgG, IgM) and NS1 Antigen Panel (test code 93192) includes NS1 antigen and IgM and IgG antibody tests. The panel may be helpful for diagnosing dengue in certain patients. Diagnostic sensitivity during early dengue infection is higher when NS1 is combined with IgM—a significant number of patients will have measurable NS1 but no measurable IgM or IgG during the first week of illness.^2,3

NS1 antigen may be ordered separately (test code 92942). An additional test, Dengue Virus RNA PCR (test code 43400), may also be useful to detect acute infection in the first five days of illness

There is no specific antiviral therapy currently available to treat dengue infection. Treatment is supportive, based on observation of hemorrhagic and circulatory abnormalities and laboratory test results (eg, electrolytes, platelets and hemoglobin).