Dengue Diagnosis in Nepal: Comparing NS1, IgG/IgM, Combo Kits, PCR, and ELISA Tests

Dengue fever remains a major health threat, particularly during the monsoon season in countries like Nepal. Early and accurate diagnosis plays a critical role in saving lives and preventing outbreaks from worsening. But with multiple diagnostic options available — including Dengue NS1 Rapid Test, IgG/IgM antibody tests, NS1 + IgG/IgM combo kits, PCR, and ELISA-based NS1 assays — how should healthcare providers choose?

Let’s break down and compare each method across important factors like time to diagnosis, cost, practicality, and healthcare efficiency.

1. Dengue NS1 Antigen Rapid Test Kits

What it Detects:

• NS1 protein antigen (secreted by the dengue virus during the early infection phase)

Best Use Window:

• Day 1 to Day 5 of fever

Features:

• Results in 15–20 minutes.
• High specificity and sensitivity during the early stage.
• Minimal training needed.
• Works well even in rural or outreach settings.
• Can be used with just Serum or plasma or Whole blood with buffer

Healthcare Efficiency:

• Excellent for emergency diagnosis, pharmacies,clinics, basic labs, primary care centers, mobile health camps.
• This kit is best for initial days of dengue fever

Cost:

• Affordable (~ NPR 400-600/test depending on volume and brand) Only few best brands including Novala products are available.

Limitations:

• Slightly lower sensitivity if tested after Day 5 of illness.
• Cannot detect previous dengue infections or immunity.

2. Dengue IgG/IgM Antibody Rapid Test Kits

What it Detects:

• IgM antibodies (appear ~5 days after infection)
• IgG antibodies (indicate past infection or secondary dengue infection)

Best Use Window:

• From Day 5 onwards of fever

Features:

• Quick results (~15–20 minutes).
• Useful for distinguishing primary vs secondary infections.

Healthcare Efficiency:

• Good tool in later stages or when NS1 antigen levels have dropped.
• Valuable for epidemiological surveillance.

Cost:

• Affordable (~ NPR 400-600/test)

Limitations:

• Poor early-stage diagnosis.
• Possibility of cross-reactivity with other flaviviruses (e.g., Zika, Japanese encephalitis, West Nile).

3. Dengue NS1 + IgG/IgM Combo Rapid Test Kits

What it Detects:

• NS1 antigen + IgG + IgM antibodies in one device.

Best Use Window:

• Day 1 to beyond Day 7 of infection.

Features:

• Combines benefits of NS1 antigen and antibody detection.
• Covers both early and late phases of infection.
• Single sample, single test format.

Healthcare Efficiency:

• Highly efficient for clinics and hospitals that want one solution.
• Reduces need for repeat testing.

Cost:

• Slightly higher than individual tests (~ NPR 800-1200/test).

Limitations:

• Slightly more complex interpretation.
• Requires good storage conditions to maintain accuracy.

4\. PCR Testing (Polymerase Chain Reaction)

What it Detects:

• Dengue viral RNA (molecular detection)

Best Use Window:

• First 5–7 days of infection

Features:

• Highly sensitive and specific.
• Can identify serotype of dengue virus (DENV-1 to DENV-4).

Healthcare Efficiency:

• Excellent for research centers, reference labs, and severe cases.
• Not practical for frontline or rural clinics.

Cost:

• Expensive (~ NPR 5000–12000/test depending on the setup).

Limitations:

• Requires a fully equipped molecular lab.
• Trained personnel needed.
• Longer turnaround time (few hours to 1–2 days).

5. ELISA-based NS1 Antigen Tests

What it Detects:

• NS1 antigen (via enzyme-linked immunosorbent assay)

Best Use Window:

• Day 1 to Day 5 of illness

Features:

• High throughput — can process 96 samples at once.
• High sensitivity and specificity.
• Better suited for hospital labs and surveillance studies.

Healthcare Efficiency:

• Good for mass testing at central hospitals during outbreaks.
• Not ideal for immediate diagnosis at the bedside.
• Less likely to be available in Nepal

Cost:

• Moderate (~ NPR 700–1500/sample).

Limitations:

• Needs lab infrastructure (incubators, washers, readers).
• Delayed results (~4–6 hours).

Quick Comparison Table

Which Test Should You Choose?

• For fast, frontline diagnosis especially in clinics, camps, and small hospitals across Nepal, Dengue NS1 Rapid Test Kits are the best first choice.
• If you want to cover both early and late-stage infection in one test, the NS1 + IgG/IgM combo kit don’t give the confirmatory results..
• PCR and ELISA-based methods are ideal for hospital laboratories, research studies, or confirmatory testing — but they are impractical for immediate, broad use in many parts of Nepal.
• Cost-effectiveness, speed, and ease of use favor rapid diagnostic tests (RDTs) like NS1 kits during Nepal’s dengue outbreaks.

Choosing the right test improves patient care, strengthens outbreak response, and saves lives.