Dengue Antigen NS1:- A positive NS1 test result confirms dengue virus infection without providing serotype information. A negative NS1 test result does not rule out infection. People with negative NS1 results should be tested for the presence of dengue IgM antibodies to determine possible recent dengue exposure.Dengue Antibody IgG:- Positive IgM and IgG tests for dengue antibodies detected in an initial blood sample mean that it is likely that the person became infected with dengue virus within recent weeks. IgM antibody tests can be positive if a person has been infected with a similar virus, such as chikungunya (called cross-reaction). Dengue Antibody IgM:- Interpretation of results. Positive IgM: Patients with a positive IgM test result are classified as presumptive, recent dengue virus infections. Negative IgM: Patients with negative IgM results before day 8 of illness and absent or negative NAAT or NS1 results are considered unconfirmed cases.