How to Interpret Dengue Test Results

Dengue fever is one of the more common ailments in India, especially during the rainy or monsoon season. It's a mosquito-borne illness caused by any one of four dengue viruses transmitted by an infected Aedes aegypti mosquito. Recovery from the disease can easily be made with timely detection and treatment. The following guide shall help understand various tests concerning dengue, the interpretation of the results derived from these tests, and further course of action.

Dengue tests types

If the doctor suspects dengue fever, he may order one or more of the following tests:

1. NS1 antigen test

• This test detects the dengue virus non-structural protein 1(NS-1).
• It works best in the early days of infection, meaning the first 5 days.
• A positive NS1 test indicates an infection with active dengue.

2. IgM antibody test

• This test is ordered to detect IgM antibodies, which your immune system produces in response to the virus that causes dengue.
• It is usually effective after the fifth day of illness.
• The appearance of IgM positivity indicates a recently acquired infection.

3. IgG antibody test

• This test detects IgG antibodies, which appear later in illness or after recovery.
• It will also show whether you had a previous infection of dengue or a secondary infection.
• Each test has a time and purpose. It is very important to tell your doctor how long you have had symptoms to get accurate results. 

Note: Many doctors will recommend multiple tests to get a complete picture.

Understanding your dengue test results

Once your tests are complete, you might receive the following results:

1. NS1 Positive

• Indicates acute dengue infection, especially in the early phase of illness.
• You must start treatment and monitoring right away.

2. IgM Positive

• Documents recent infection with dengue, usually after the fifth day of illness.
• This result confirms that your body is fighting the virus.

3. IgG positive

• Suggests infection in the past.
• If this is also about a positive IgM result, it may be able to show a secondary infection, which can be far worse.

4. Positive for IgM and IgG

• Confirms active dengue infection and usually indicates a secondarily infected individual.

5. Equivocal or negative results

• Equivocal means the test was unclear, and a repeat may be necessary.
• Negative findings most likely indicate that you may be free from dengue, but your doctor will look towards other possibilities depending on how you are feeling.
• These results are not sufficient on their own. Physicians make a diagnosis with the help of your symptoms, case history, and physical examination.

IgM and IgG antibody tests: Detailed explanation

Understanding the relationship between IgM and IgG results is vital in defining the type and the stage of dengue infection.

1. IgM Positive, IgG Negative

• It suggests that the infection is of primary dengue, hence this is the first time one gets dengue.
• Usually seen in the early stages of the illness.

2. IgM Negative, IgG Positive

• Suggests infection in the past.
• You are not currently infected but have immunity from a previous infection.

3. Both IgM and IgG Positive

• Indicates an active secondary infection.
• Secondary infections are more dangerous because of an exaggerated response of immunity.

4. Both negative

• This means you are unlikely to have dengue, although in such cases, the doctor could well order a repeat for both.
• This will help them to identify the stage and seriousness of your condition. Always consult your doctor for an accurate interpretation.

Importance of medical advice and monitoring symptoms

Dengue infection can indeed be anything from mild to life-threatening. However, as important as the results of such tests are, monitoring signs and symptoms is just about equally important.

Common symptoms of dengue include:

• High fever over 102°F
• Headache and pain behind the eyes
• Joint and muscle pain; so-called "breakbone fever”
• Rash (red spots on skin)
• Nausea and vomiting
• Warning Signs of Severe Dengue:
• Bleeding from the gums or nose
• Blood in the urine or stools
• Severe abdominal pains
• Persistent vomiting
• Difficulty breathing

If any of the warning signs appear, urgent medical care is needed. If left unmanaged, severe dengue may lead to complications like organ impairment, shock, and even death.

Next steps after dengue testing

Once your test results come in, here's what you should do:

If your test is negative

• Watch your symptoms carefully.
• Dengue tests can be negative in the initial days. You might require a repeat test.
• Look for other ailments if symptoms persist.

If your test is positive

• Follow your doctor's advice: Start medication right away.
• Stay Hydrated: Drink lots of water, coconut water, and ORS.
• Monitor Platelet Count: Dengue is usually associated with low platelets, which may lead to bleeding.

If results are equivocal

• Discuss retesting with your doctor.
• Continue monitoring your symptoms.
• Acting quickly after your results ensures better recovery and reduces the risk of complications.

The importance of early detection of dengue

In dengue, timing is everything. Early detection allows for proper monitoring and prevents the disease from becoming severe.

Benefits of early detection

1. Effective monitoring: The doctor would be able to monitor your platelet count and detect an impending problem.
2. Symptom management: Medication is given to reduce fever and pain.
3. Early action prevents severe cases of dengue or dengue hemorrhagic fever.

Awareness is necessary, especially in India, where the outbreaks of dengue are very frequent. If one has the symptoms or knows of someone who does, do not wait; just get tested.

What to do if your dengue test comes out positive?

Testing positive for dengue can be a harrowing experience. Here's a step-by-step guide on how to cope with it.

1. Start treatment

• Take a rest.
• Take medications, especially for fever, which your doctor will recommend; these include paracetamol. 
• Avoid the use of NSAIDs such as ibuprofen due to increased risks of bleeding.

2. Stay hydrated

• Dehydration is common in dengue. Drink plenty of fluids, such as water, soups, or oral rehydration solutions. 

3. Monitor symptoms

• Watch for symptoms such as bleeding, extreme pain, or even dizziness.
• Go to the hospital at once if the symptoms worsen.

4. Avoid mosquito bites

•  Mosquito nets and repellents to avoid infecting others. 
• The period of recovery usually takes 1 to 2 weeks, though for severe symptoms, full recovery may take longer. 

Other Tests for Diagnosis of Dengue Fever Apart

Other tests for diagnosing dengue fever aside from NS1, IgM, and IgG tests, doctors may recommend the following blood tests to evaluate the severity of dengue infection:

1. Complete blood count (CBC) 

Check for low platelet count and hematocrit levels. Low platelets increase the risk of bleeding, and high hematocrit suggests dehydration. Know more about your CBC.

 2. Liver function test (LFT) 

Dengue can affect your liver. This test is to find out whether you have high liver enzymes, which is a sign of damage. 

3. Ultrasound or chest X-ray

 It can detect fluid accumulation in severe cases, especially in the abdomen or lungs. These tests will help the doctor make informed decisions about your treatment and care. 

Dengue fever is serious, but early detection, and proper treatment, with careful monitoring, ensure a full recovery. Always consult a healthcare professional for guidance, and take precautions to prevent mosquito bites. Stay informed, stay safe!

Conclusion

Dengue is serious but treatable with early detection and proper care. Regular health check-ups help catch warning signs early. Stay informed, consult a doctor, and take preventive steps to stay safe. TruePal offers health check-up services tailored to your needs to help you stay on top of your health.

FAQs

1. What are the common types of tests used to diagnose dengue?

A PCR test (polymerase chain reaction) is a molecular test used to detect dengue. These tests can be performed within the first seven days after your symptoms appear. Later tests may produce inaccurate results.

2. How is a dengue test result interpreted?

Patients who get a positive IgM test result in a single sample are presumed to have recently contracted the dengue virus. Patients having a negative IgM test between days 0-7 of illness, along with absent or negative NS1, are considered unconfirmed instances.

3. What is considered a positive dengue test result?

A positive dengue test indicates infection. The NS1 antigen or RT-PCR confirms active infection early. IgM antibodies suggest recent infection, while IgG antibodies indicate past or secondary exposure. Results should align with symptoms like fever, rash, and joint pain. Consult a doctor for accurate diagnosis and treatment.

4. What does a negative dengue test result mean?

A negative dengue test usually means no active infection, but timing matters. Early tests like NS1 antigen or RT-PCR may miss the virus if done too soon. Negative IgM or IgG antibodies suggest no recent or past infection. Always consider symptoms and consult a doctor for confirmation.