More on the test...

Dengue Fever
Dengue fever is a viral disease transmitted by mosquitoes (Aedes aegypti and Aedes albopictus) and caused by four serotypes of dengue virus (DEN): DEN-1, DEN-2, DEN-3, and DEN-4. Transmitted by the main vector, the Aedes aegytpi mosquito, there are four distinct, but closely related, viruses that cause dengue. Recovery from infection by one provides lifelong immunity against that serotype but confers only partial and transient protection against subsequent infection by the other three. There is good evidence that sequential infection increases the risk of more serious disease resulting in DHF. Mosquitoes are widely distributed throughout the tropical and subtropical areas of the world.

In children infection is often subclinical or causes a self limited febrile disease. However, If patient is infected second times with a different serotype, a more severe disease, dengue hemorrhagic fever or dengue shock syndrome, is more likely to occur. Dengue is considered to be the most important arthropod-borne viral disease due to the human morbidity and mortality it causes. NS1 is a highly-conserved glyco-protein that is present at high concentrations in the sera of dengue infected patients during the early clinical phase of the disease. NS1 antigen is found from the first day and up to 9 days after onset of fever in the sample of primary or secondary dengue infected patients. Usually IgM does not become detectable until 5-10 days after the onset of illness in cases of primary dengue infection and until 4-5 days after onset of illness in secondary infections. In primary infections, IgG appear the 14th day and persist for life. Secondary infections show that IgGs rise within 1-2 Days after the onset of symptoms and induce IgM response after 20 days of infection.