IgG ELISA for dengue is a blood test that detects IgG antibodies produced against the dengue virus. A positive IgG indicates past infection or a later-stage/secondary infection, since IgG typically appears about 7–10 days after symptom onset and can persist for months to years. It’s useful for serosurveys and confirming prior exposure but can cross-react with other flaviviruses and isn’t ideal alone for early diagnosis.

Dengue IgG positive means antibodies to dengue virus are present, indicating past exposure or a later/secondary immune response rather than necessarily current acute infection. IgG appears weeks after infection and can persist for years. Interpretation requires clinical context and other tests (IgM, PCR); cross-reactivity with other flaviviruses can occur. A clinician can clarify timing, immunity implications, and risk for severe disease with different serotypes.

The ELISA IgG test (enzyme-linked immunosorbent assay) detects IgG antibodies in blood against a specific pathogen or antigen. It uses antigen-coated wells and an enzyme-linked antibody to produce a measurable color change. A positive IgG generally indicates past infection or immune response, often appearing weeks after exposure and persisting; results may be qualitative or quantitative and require clinical correlation.

Most dengue ELISA kits report an index or S/CO ratio. A common cutoff is index ≥1.1 (or S/CO ≥1.0) as positive; 0.9–1.1 is equivocal/indeterminate; <0.9 is negative. Some kits use units (for example, >11 units positive, 9–11 equivocal). Always interpret against the specific kit’s reference ranges and clinical timing (NS1, IgM, IgG).

Dengue IgG ELISA test costs vary by country and facility. In India private labs typically charge about ₹500–₹2,000. In the United States expect roughly $50–$200 (higher if billed through hospitals). In the UK testing is usually free via the NHS; private labs may charge about £30–£100. Exact prices depend on location, facility, and any additional services.

A dengue ELISA shows NS1 antigen, IgM and IgG results. NS1 positive indicates acute infection in early illness (first ~5 days). IgM positivity suggests recent infection (appears around day 3–5, peaks week 2). IgG indicates past exposure or secondary infection; high IgG with low/absent IgM favors secondary dengue. Correlate with symptoms, illness day, repeat testing or PCR for confirmation.