If a dengue test shows IgM positive or IgG positive, the meaning depends on which antibody is detected:
- IgM positive: Usually suggests a recent or current dengue infection. IgM antibodies typically appear about 4–5 days after symptoms begin and can remain detectable for several weeks to months.
- IgG positive: Usually indicates a past dengue infection. IgG antibodies develop later and can remain in the body for years. However, a very high or rapidly rising IgG level may also occur during a secondary dengue infection (when someone gets dengue again with a different dengue virus type).
- Both IgM and IgG positive: May indicate a recent infection, especially if the person has had dengue before.
To interpret the result accurately, doctors also consider:
- The person’s symptoms
- How many days they have been ill
- Other test results, such as the dengue NS1 antigen test or PCR testing
If you have the exact test report (including IgM, IgG, and NS1 results), I can help explain what it means.