Finding the right tests…
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Emergency services available 24 x 7
Finding the right tests…
Serology
DENGUE IGG & IGM orders both dengue antibody tests from a single sample, so your doctor gets IgM and IgG results together rather than requesting them separately. Reading the two side by side does more than confirm a dengue antibody response — the balance between them helps show whether this is likely a first dengue infection or a second one, since IgG tends to rise faster during a repeat infection than during a first exposure. This distinction matters because a second dengue infection carries a real risk of more severe illness. Your doctor typically orders this combined test a few days into a fever that looks like dengue, once both antibodies have had time to develop.
From one blood sample, this test returns two separate readings — a dengue IgM result and a dengue IgG result — each reported as positive or negative, plus how the two compare to each other. A relatively higher IgM against IgG points toward a first dengue infection, while a relatively higher IgG against IgM points toward a repeat infection, particularly early in illness. Because both antibodies take some days to build up, this combined test works best once you're several days into your illness rather than on the first day of fever.
Your first dengue infection and a repeat dengue infection produce different antibody patterns, and reading IgM and IgG together is how your doctor tells them apart from a single blood draw. In a first infection, IgM tends to rise well before IgG, and IgG often stays weak or absent for the first week. In a repeat infection, prior exposure means your immune system already knows how to make IgG, so it can rise quickly, sometimes strongly enough that IgG outweighs IgM even early in the illness.
Secondary dengue infections carry a meaningfully higher risk of complications, including hemorrhagic manifestations and severe illness, compared with a first infection, according to research on IgM/IgG patterns in dengue. Flagging a likely secondary infection early can prompt closer monitoring.
This combined test is a helpful early clue, not a definitive answer. Both antibodies need several days to build up, so testing too early in a fever can under-read either value, and cross-reaction with other related viruses can occasionally complicate interpretation. Your doctor may still want NS1 or a repeat sample to build a complete picture.
Reading both from one sample lets your doctor compare them directly, which can suggest whether this is your first dengue infection or a repeat one, information a single antibody alone wouldn't give.
A relatively higher IgG, especially early in illness, points toward a repeat dengue infection, since your immune system already knows how to make IgG quickly from a past exposure.
One study from India found a dengue IgM-to-IgG ratio above 1.59 suggested a first infection and below it suggested a repeat infection, though cut-offs vary between studies and labs. Ranges vary by lab, so ask your doctor how your report's result was calculated.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
Research on IgM/IgG patterns has linked secondary dengue infections to a higher risk of complications, including hemorrhagic symptoms and severe illness, than a first infection.
Not entirely. NS1 detects the virus itself and is more useful in the very first days of fever, while IgM and IgG need more time to build up, so your doctor may still use NS1 alongside this test early in an illness.
This test is most informative once you're several days into your illness, since both antibodies need time to rise; ask your doctor about the right timing for your situation.
No. No special preparation, including fasting, is needed before this blood draw.