Dengue IgG

A positive dengue IgG indicates prior exposure or a later-stage/recovered dengue infection. IgG antibodies typically appear after the first week and can persist for months to years, suggesting some immunity to that serotype. It does not necessarily indicate an acute recent infection—IgM or PCR are used for early diagnosis. Clinical correlation and physician evaluation are recommended, as prior infection may affect risk with different serotypes.

IgM and IgG are two antibody types with different timing and functions. IgM is a large pentamer produced first during acute infection; it agglutinates pathogens and strongly activates complement. IgG is a smaller monomer that appears later, provides long-term immunity and memory, neutralizes pathogens, opsonizes, and can cross the placenta to protect the fetus. IgG levels persist longer than IgM.

Dengue IgG antibodies usually appear after infection and can persist for years—often remaining detectable lifelong—indicating past exposure. They give long-term, mainly serotype-specific protection but may wane and do not guarantee immunity against other serotypes. Prior infection can sometimes increase severity of a later infection with a different serotype (antibody-dependent enhancement). A positive IgG shows exposure, not exact protection.

Do dengue IgM testing from about day 4–5 after fever onset (IgM peaks at 2–3 weeks and may persist for months). IgG appears around days 7–10 and rises in convalescence; high or rising IgG suggests past exposure or secondary infection. Best practice: collect an acute sample at presentation and a convalescent sample 10–14 days later. Use NS1 antigen or PCR in the first 1–5 days.

A positive IgG usually indicates past exposure or developed immunity rather than an active infection. Interpretation depends on the specific test, timing, presence of IgM, symptoms and your immune status. False positives can occur. If you’re asymptomatic and your clinician is unconcerned, immediate action is often unnecessary; seek medical follow-up if you have symptoms, recent exposure, or are immunocompromised.

A dengue IgG–positive result usually indicates past infection and needs no specific treatment if you’re well. If symptomatic, management is supportive: rest, plenty of oral fluids, paracetamol for fever/pain, and strict avoidance of NSAIDs/aspirin. Monitor blood counts and watch for warning signs (severe abdominal pain, persistent vomiting, bleeding, drowsiness); seek urgent care if they occur. Practice mosquito protection.