How Accurate Are Dengue Tests? What You Need to Know

Dengue fever is a mosquito-borne viral disease that infects millions of people every year worldwide. It is, therefore, crucial to make a correct diagnosis of this fever based upon symptoms. Symptoms are high fevers, body aches, headaches, rashes, and vomiting, and thus it becomes extremely important to confirm a diagnosis of dengue: none of the antiviral drugs nor a vaccine currently exist that could treat or prevent the disease. Thus, accurate interpretation becomes of grave importance.

The crux of this article will delve into the accuracy of dengue tests, the best methods of diagnosing the virus, and why Mahajan Imaging & Labs is one of the best-ensured references in dengue testing.

How Reliable Are Dengue Tests?

Dengue test accuracy depends on several factors:

The infection phase upon which the test is conducted
The test type used in the detection
The sample collected quality
The credibility of the laboratory conducting the test

Dengue tests are generally categorised into two types: direct virus detection and antibody detection. The test to be conducted is based on the duration of the patient’s symptoms. Mahajan Imaging & Labs employs highly advanced diagnostic technology to provide highly reliable results, thus minimizing the possibility of misdiagnosis.

Types of Dengue Tests and Their Accuracy

Mahajan Imaging & Labs employs three primary dengue diagnosis techniques to provide accurate and timely diagnosis:

1. PCR Test for Dengue – The Gold Standard for Early Detection

What It Detects: The dengue virus’s genetic material (RNA) in a blood sample.
When It’s Most Effective: The virus is present and actively flowing in the blood during the first seven days of infection.
Accuracy: Very high since PCR tests directly identify the virus and not the body’s immune response.
Why It’s Recommended:
- Gives a conclusive diagnosis with almost 100% specificity.
- Identifies all four serotypes of the dengue virus.
- Rules out cross-reactivity with other viral infections.

PCR tests are among the best diagnostic tests for dengue, particularly for early diagnosis. Mahajan Imaging & Labs provides state-of-the-art PCR-based dengue testing with fast and highly accurate results.

2. NS1 Antigen Test – Best for Rapid Early Diagnosis

What It Tests For: The NS1 protein (a viral antigen) in the blood.
When It Works Best: Within five days of the onset of illness before the body begins to mount its antibody response.
Accurate: It is susceptible, especially during the early infection period. Sensitivity drops as the virus clears from the circulation.
Why It’s Recommended:
- It enables quick detection.
- Differentiates dengue from other febrile illnesses.
- It is best used for patients during the initial few days of fever when antibody tests are effective.

At Mahajan Imaging & Labs, the NS1 Antigen Test is performed on advanced diagnostic machinery for quick and accurate results.

3. ELISA Test for Dengue (IgM & IgG Antibody Test) – Identifying Past and Current Infections

What It Detects: IgM and IgG antibodies that represent the body’s immune response against the dengue virus.
When It’s Most Effective:
- IgM appears on day 4-5 of the disease course and remains in the bloodstream for weeks or months.
- IgG appears much later, indicating the past infection or immunity most likely due to some previous exposure.
Accuracy:
- The IgM ELISA is very sensitive to denga that has occurred a week or so prior to undertaking the test. However, false-positive reactions can occur, attributable to cross-reactivity with other viruses.
- The IgG ELISA can indicate past infections, but it cannot be used to characterize acute cases.
Why It’s Recommended:
- It assures the diagnosis of dengue after the first week of the disease.
- It determines whether the infection was primary (first infection) or secondary (subsequently).

Dengue ELISA tests at Mahajan Imaging and Labs are completely automated, assuring accuracy and reliability of these tests.

Factors That Affect Dengue Test Accuracy

Although dengue diagnostic techniques have improved greatly, some factors can affect test results. Knowing these variables can assist patients and physicians in interpreting results appropriately.

1. Timing of the Test

Early testing before the virus can be detected, or late testing after the virus has already been cleared may yield false negatives.
PCR and NS1 tests are optimal within the first 5-7 days, while ELISA antibody tests are optimal after one week.

2. Cross-reactivity with Other Viruses

Dengue belongs to the Flavivirus family, which includes Zika and Chikungunya.
Serological tests might produce false positives due to cross-reactivity with these viruses.

3. Sample Collection and Handling

Inadequate sample collection practices can provide invalid results.
At Mahajan Imaging & Labs, each step—from sample collection to testing—is performed under rigorous quality control measures to guarantee maximum accuracy.

Why Choose Mahajan Imaging & Labs for Dengue Diagnosis?

With years of experience in cutting-edge diagnostic testing, Mahajan Imaging & Labs is dedicated to delivering accurate and reliable dengue detection results.

Here’s why we are a trusted name in dengue testing:

State-of-the-art technology – Providing highly precise PCR, NS1, and ELISA tests.
Quick and effective processing – Receive results promptly.
Trained pathologists and technicians – Offering accurate diagnostics and expert opinion.
Convenient online booking – Book a Dengue Test Appointment Online and spare yourself unnecessary delays.

Accuracy is paramount when it comes to laboratory tests for detecting dengue fever. We at Mahajan Imaging & Labs focus on the highest testing standards to enable patients to receive the best care.

Quick Answers To Your Concerns:

What are the three tests for dengue?

The three main tests for dengue include:

PCR Test – Identify the virus’s genetic material; ideal to identify early on (first 7 days).
NS1 Antigen Test – Identify the dengue virus NS1 protein; ideal during the first 5 days from symptoms.
ELISA Test (IgM & IgG Antibody Test) – Determine immune system produced antibodies; best done after week 1.

What is dengue IgM, IgG, and NS1?

IgM antibodies suggest a recent dengue infection and can be detected 4-5 days following symptom onset.
IgG antibodies suggest past infection or immunity due to a past dengue infection.
NS1 Antigen is a viral protein itself from the dengue virus, traceable in the bloodstream during the first few days of infection.

What is the CBC test for dengue?

A Complete Blood Count (CBC) test aids in tracking the effect of dengue on blood cells, especially:

Low platelet count (thrombocytopenia) – A common dengue complication.
Low white blood cell count (leukopenia) – Suggests viral infection.
Increased hematocrit levels – Refers to plasma leakage, a sign of severe dengue.