Dengue IgG/IgM vs NS1 Rapid Tests: What Should Distributors Know?

Dengue rapid tests are available in multiple configurations: NS1 antigen only, IgG/IgM antibody only, or combination products that include NS1 and antibodies together. For distributors, the key procurement questions involve understanding which configuration matches the local testing algorithm, specimen requirements, detection windows and regulatory pathway.

NS1 antigen testing

NS1 (nonstructural protein 1) is a dengue viral antigen that may be detectable in blood from the first day of fever through approximately the first week of illness. An NS1-only test targets early detection before the antibody response develops. This can support early clinical decisions, but sensitivity may decline as the illness progresses.

Distributors should confirm the specimen type (serum, plasma, whole blood), collection and handling requirements, and the intended setting. NS1 tests are generally positioned for acute-phase screening in clinical or laboratory environments.

IgM and IgG antibody testing

IgM antibodies typically appear around day four to five of illness and may remain detectable for weeks to months. IgG antibodies appear later in primary infections but may rise earlier in secondary infections due to prior dengue exposure. Antibody tests are useful for confirming recent or past infection, but they are less suited to detecting acute illness in the first few days of fever.

Procurement considerations include whether the test distinguishes between IgM and IgG on separate lines, the specimen type, and whether the intended use covers primary and secondary infection interpretation.

Combination products

A combination dengue rapid test detects NS1, IgM and IgG on a single device. This configuration can extend the detection window across both early and later stages of illness. For distributors, combination products may simplify inventory management and cover more clinical scenarios with one SKU.

However, a combination test is not a substitute for confirmatory laboratory methods. Each analyte has its own detection window and clinical interpretation. Distributors should ensure that the instructions for use and marketing materials accurately reflect the test's scope and limitations.

Procurement questions

Before selecting a dengue rapid test configuration, distributors should clarify the following:

• What is the local testing algorithm or guideline? Does it recommend NS1 alone, antibody alone, or both?
• What specimen types are acceptable for the intended user setting?
• What evidence is available for the specific product configuration (not just the manufacturer's general portfolio)?
• What are the local registration, tender or import requirements?

These questions help match the product to the real-world workflow rather than selecting based on price or general familiarity alone.

A portfolio decision

In endemic regions, a distributor may carry both an NS1-only product for early-phase screening and a combination product for broader coverage. In other markets, a single combination SKU may be sufficient. The right portfolio depends on clinical demand, user preference, competitive positioning and regulatory status in each destination country.

PRISES offers dengue rapid test configurations for distributor and OEM partners. Product-specific documentation, sample availability and destination-market suitability should be confirmed for each project.