Infections & SerologyNo Fasting RequiredTurnaround: 2–4 hours (rapid / same day)

Dengue Serology (NS1 Antigen, IgM & IgG)

Also known as: Dengue NS1 Antigen, Dengue IgM/IgG, Dengue Fever Profile, Dengue Duo Test

Parameters Measured in the Report

A breakdown of individual biomarkers and biological reference intervals typically found in your report:

Biomarker	Standard Range	Unit	What It Means
Dengue NS1 Antigen (NS1 Ag)	Negative (Non-Reactive)	qualitative / index	Viral protein detected during early acute phase (Days 1–5 of fever).
Dengue IgM Antibody (IgM)	Negative (Non-Reactive)	qualitative / index	Primary immune response antibody; turns positive around Day 5 and persists for 2–3 months.
Dengue IgG Antibody (IgG)	Negative (Non-Reactive)	qualitative / index	Indicates past exposure; rapid high-titer surge denotes secondary infection (higher hemorrhagic risk).

* Note: Reference ranges may vary slightly between testing instruments and reagent kits. Always refer to the reference interval printed on your specific pathology report.

Clinical Focus

Dengue virus non-structural protein 1 (NS1) antigen and host-produced IgM and IgG immunoglobulins.

Sample & Specimen

Venous blood (Serum tube)

Fasting Protocol

No fasting required. Urgent test performed upon clinical presentation.

Turnaround Time

2–4 hours (rapid / same day)

What Is This Test?

Dengue Serology is an essential diagnostic profile for identifying acute infection with the mosquito-borne Dengue flavivirus (serotypes DEN-1 to DEN-4), transmitted by *Aedes aegypti* mosquitoes. The infection progresses in phases: acute febrile phase (days 1–5), critical plasma leakage phase (days 5–7), and convalescence. During early fever (days 1 to 5), the **Dengue NS1 Antigen** test detects viral protein circulating in blood. From day 5 onward, as the virus clears, host **IgM antibodies** appear confirming primary acute infection, while **IgG antibodies** indicate past infection or secondary infection with a different serotype.

Why Did Your Doctor Order This Test?

Physicians routinely prescribe the Dengue Panel in the following clinical scenarios:

Sudden onset high-grade fever (103°F–104°F) accompanied by severe retro-orbital eye pain, headache, and severe joint/muscle pain ("breakbone fever")

Nausea, vomiting, flushed skin, or measles-like rash in dengue-endemic geographic areas or post-travel

Follow-up in febrile patients showing progressive drops in platelet count (<100,000 /µL) or rising hematocrit on CBC

Warning signs of severe dengue: persistent vomiting, mucosal bleeding (gum bleed, nosebleed), abdominal pain, or lethargy

How to Prepare Before Your Test

Fasting Requirement: No fasting required. Urgent test performed upon clinical presentation.

No fasting or special preparation required.

Understanding Your Results

What higher or lower readings generally mean in clinical practice:

If Values Are Higher Than Normal

A positive NS1 Antigen or positive IgM confirms acute Dengue virus infection. If Dengue IgG is strongly positive early alongside NS1/IgM, it signifies a Secondary Dengue Infection, carrying a significantly higher risk for Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS).

If Values Are Lower Than Normal

Negative serology in the first 24 hours of fever can occasionally occur before antigen peaks. If clinical suspicion remains high, CBC platelet monitoring and repeat testing on day 3–4 is advised.

Frequently Asked Questions

Why is it critical to check platelet counts in a dengue-positive patient?

Dengue virus induces bone marrow suppression and immune destruction of platelets. When platelets drop below 20,000–50,000 /µL alongside plasma leakage (rising hematocrit), patients are at risk for internal hemorrhage requiring close inpatient monitoring.

Related Laboratory Tests

Tests frequently prescribed together or used as follow-up investigations:

Complete Blood Count (CBC / Hemogram)

Counts and evaluates red blood cells, white blood cells, hemoglobin, hematocrit, and platelets.

Liver Function Test (LFT / Hepatic Panel)

Bilirubin fractions, transaminases (ALT/SGPT, AST/SGOT), Alkaline Phosphatase (ALP), and proteins (Albumin, Globulin).

Widal Test & Typhidot (Enteric / Typhoid Fever)

Serum agglutinating antibody titers against Salmonella enterica serovar Typhi O (somatic) and H (flagellar) antigens.

Medical & Diagnostic Disclaimer

This guide is published for educational and patient informational purposes only. It is not a substitute for professional medical evaluation, diagnosis, or clinical advice.

A laboratory result that falls slightly outside standard statistical reference intervals does not automatically indicate disease; conversely, a normal result does not guarantee the absence of medical conditions. Only your attending physician can interpret lab findings in the context of your medical history, physical exam, and symptoms.