Dengue NS-1 Antigen (ELISA)

Bacterial/ Viral

Report in 12Hrs

At Home

No Fasting Required

Details

Test for detecting dengue virus (NS1 antigen or IgM antibodies) in suspected dengue fever cases.

₹399₹660

40% OFF

Dengue NS-1 Antigen (ELISA) - Comprehensive Test Information Guide

Why is it done?
- Test Purpose: Detects NS-1 (Non-Structural 1) antigen produced by dengue virus during acute infection; used for early diagnosis of dengue fever within the first 7-10 days of symptom onset
- Primary Indications: Suspected dengue fever with acute symptoms (fever, headache, myalgia, rash); screening in endemic areas; confirmation of dengue in patients presenting with fever and clinical features consistent with dengue virus infection
- Typical Timing: Performed during acute phase of illness (days 1-7 after symptom onset); most sensitive during first 5 days; can remain positive for up to 10-14 days in some cases; ideal for early diagnosis before IgM antibodies become detectable
Normal Range
- Reference Values: Negative (Non-Reactive) - Absence of dengue NS-1 antigen; Positive (Reactive) - Presence of dengue NS-1 antigen indicating acute dengue infection
- Units: Semi-quantitative (typically reported as Non-Reactive/Negative or Reactive/Positive); some labs provide optical density (OD) values or index values with cutoff thresholds
- Result Interpretation: Negative - No dengue NS-1 antigen detected; suggests no acute dengue infection or testing performed too late after symptom onset; Positive - Dengue NS-1 antigen detected; indicates active dengue virus infection; Borderline/Equivocal - Results between negative and positive cutoff thresholds may require repeat testing or confirmatory tests
- Clinical Significance: Normal (Negative) result indicates no acute dengue infection detected; Abnormal (Positive) result confirms acute dengue virus infection and warrants clinical management and epidemiological investigation
Interpretation
- Positive NS-1 Antigen Result: Confirms active dengue virus infection during acute phase; indicates patient has circulating dengue virus and is potentially infectious; suggests early viremia with high viral load; warrants clinical monitoring for progression to severe dengue or dengue hemorrhagic fever
- Negative NS-1 Antigen Result: Does not rule out dengue infection; if collected after day 7-10 of illness, NS-1 antigen may have declined below detection threshold; if performed in first 3 days with high clinical suspicion, false negative possible but less likely; recommend follow-up with IgM antibody testing or repeated NS-1 testing
- Factors Affecting Results: Timing of specimen collection relative to symptom onset (sensitivity decreases after day 10); dengue serotype involved (all serotypes detectable); viral load variation; immune status of patient; specimen quality and handling; test methodology and laboratory standards
- Clinical Significance Patterns: Positive NS-1 + Positive IgM = Recent dengue infection (acute phase); Positive NS-1 + Negative IgM = Very early dengue infection (first 3-5 days); Negative NS-1 + Positive IgM = Later acute or early convalescent phase; Negative NS-1 + Negative IgM = Either non-dengue illness or dengue ruled out depending on timing
- Sensitivity and Specificity: Sensitivity ranges from 50-90% depending on days since symptom onset (higher in first 5 days, lower after day 10); Specificity >95% for dengue detection; high positive predictive value in endemic areas; negative result does not exclude dengue, especially if tested after acute phase
Associated Organs
- Primary Organ Systems Affected: Hematopoietic system (blood and bone marrow); Lymphatic system; Vascular endothelium; Liver (hepatic involvement); Central nervous system (in severe cases); Gastrointestinal tract
- Conditions Associated with Positive Results: Dengue Fever (classical dengue); Dengue Hemorrhagic Fever (DHF); Dengue Shock Syndrome (DSS); Secondary dengue infection (re-infection with different serotype); Primary dengue infection; Asymptomatic dengue viremia
- Dengue-Related Complications: Hemorrhagic manifestations (bleeding from mucous membranes, petechiae, ecchymosis); Thrombocytopenia (low platelet count); Hepatomegaly and liver dysfunction; Plasma leakage and hypovolemic shock; Encephalitis (dengue-associated neurological complications); Myocarditis; Acute kidney injury in severe cases
- Dengue Diagnostic Context: NS-1 antigen test helps confirm dengue diagnosis in symptomatic patients; differentiates dengue from other febrile illnesses; essential for disease surveillance and outbreak investigation; guides clinical management decisions; supports epidemiological tracking of dengue transmission
- Risk Stratification: Positive NS-1 result indicates need for close clinical monitoring; warrants evaluation for warning signs (abdominal pain, persistent vomiting, bleeding, lethargy); secondary dengue infection poses higher risk for severe dengue; pregnant patients and very young/elderly populations at increased risk for complications
Follow-up Tests
- Recommended Follow-up Tests: Dengue IgM Antibody (ELISA) - for confirmation if NS-1 negative or inconclusive, especially after day 5 of illness; Dengue IgG Antibody - to assess for previous dengue exposure or secondary infection; Dengue Virus PCR (Reverse Transcriptase PCR) - gold standard for dengue confirmation; can identify specific serotype
- Supportive Laboratory Tests: Complete Blood Count (CBC) - assess for thrombocytopenia and hematocrit changes; Liver Function Tests (LFTs) - monitor hepatic involvement; Coagulation Profile (PT, PTT, INR) - evaluate bleeding tendency; Renal Function Tests - monitor kidney involvement in severe cases; Electrolytes - assess for hyponatremia or electrolyte imbalances
- Further Investigations for Severe Dengue: Ultrasound abdomen - assess for plasma leakage, pleural effusion, ascites; Chest X-ray - detect pulmonary involvement or pleural effusion; Blood cultures - rule out secondary bacterial infection; Cardiac markers and ECG - if myocarditis suspected; Lumbar puncture with CSF analysis - if neurological complications suspected
- Monitoring Frequency: Acute phase: Daily or twice-daily monitoring during first week; Critical phase (days 3-7): Close monitoring every 4-6 hours if hospitalized; Recovery phase: Less frequent monitoring as clinical status improves; Repeat NS-1 or PCR testing not typically indicated if positive; IgM testing recommended if NS-1 negative and clinical suspicion remains high
- Related Complementary Tests: Rapid Dengue Combo Tests - detect NS-1, IgM, and IgG simultaneously; Multiplex PCR panels - detect dengue alongside other viral pathogens (influenza, COVID-19); Serotype-specific RT-PCR - determine which dengue serotype responsible; Viral sequencing - for epidemiological surveillance and outbreak investigation
- Clinical Decision Pathways: Positive NS-1 + Normal CBC: Clinical observation and symptomatic management; Positive NS-1 + Thrombocytopenia: Close monitoring for progression to DHF; Positive NS-1 + Signs of plasma leakage: Consider hospitalization and fluid management; Negative NS-1 (days 1-3 of illness): Repeat testing or proceed with PCR; Negative NS-1 (days 4-10): Recommend IgM testing
Fasting Required?
- Fasting Requirement: NO - Fasting is NOT required for Dengue NS-1 Antigen (ELISA) testing
- Specimen Collection Requirements: Blood sample (serum or plasma) can be collected at any time of day; No specific dietary restrictions; Patient may eat and drink normally before test; Test can be performed regardless of time since last meal
- Medication Considerations: No specific medications need to be avoided before test; Patients may continue regular medications; Anti-pyretics (acetaminophen, ibuprofen) can be used for symptom relief and do not affect test results; Anticoagulants do not affect dengue NS-1 antigen detection
- Patient Preparation Instructions: Wear loose, comfortable clothing for easy blood draw; Inform phlebotomist of any needle phobias or previous difficult blood draws; Remain seated or lie down for 5-10 minutes after blood collection to prevent dizziness; Maintain adequate hydration (drink water before test to aid vein visibility); Bring identification and insurance information
- Special Instructions: Optimal timing: Collect sample within first 10 days of symptom onset (peak sensitivity days 1-5); Clearly label specimen with patient details and collection time; Ensure proper tube (typically serum separator or EDTA tube depending on lab protocol); Keep specimen at appropriate temperature (typically room temperature or 2-8°C depending on transport time); Transport to lab promptly (preferably within 24 hours)
- Post-Collection Care: Apply light pressure to puncture site for 2-3 minutes to prevent hematoma; May remove bandage after a few minutes; Resume normal activities immediately; Avoid strenuous exercise for remainder of day; Drink extra fluids to replace lost blood volume; Contact laboratory if site shows signs of infection or persistent bleeding

How our test process works!