But there is no single "dengue test". There are three, and each works best at a different stage of the illness. Taking the wrong one on the wrong day is the most common reason a dengue result comes back negative when the person really has dengue.
This guide explains what the NS1, IgM and IgG tests measure, which day of fever each one is useful, why the platelet count matters, and what the tests cost on SecondMedic.
The three dengue tests at a glance
| Test | What it detects | Most useful |
|---|---|---|
| NS1 antigen | A protein made by the dengue virus itself | Days 1 to 5 of fever |
| IgM antibody | The body's early antibody response | From about day 5 onwards |
| IgG antibody | The later, long-lasting antibody | Later in the illness; also shows past infection |
NS1 antigen test: for the first days of fever
NS1 is a protein released by the dengue virus into the blood. It can usually be detected from the first day of fever until about day 5, and sometimes a little longer. Because it looks for the virus rather than the body's response, it is the test to choose early. After the first week NS1 levels fall, so a negative NS1 later in the illness does not rule dengue out.
IgM antibody test: from about day 5
IgM is the first antibody the immune system makes against dengue. It usually becomes detectable around the fifth day of illness, peaks over the next two weeks and can stay positive for two to three months. A positive IgM points to a recent dengue infection. Tested too early, IgM can be negative simply because the body has not made it yet.
IgG antibody test: later infection or past exposure
IgG appears later, usually in the second week of a first infection, and can remain for years. In a second dengue infection, IgG often rises quickly and early. A positive IgG on its own may only mean a past infection, which is common in India, so doctors read it together with IgM, NS1 and the symptoms.
Which dengue test should you take?
- Fever for 1 to 4 days: the NS1 antigen test, ideally with IgM, because together they cover both the early and the later window.
- Fever for 5 days or more: IgM and IgG antibody tests, with NS1 if your doctor advises.
- Not sure how long, or symptoms are changing: a combined profile with NS1, IgM and IgG avoids having to guess the day.
The Jaanch Dengue Profile includes all three (NS1, IgM and IgG by ELISA) together with a complete blood count, so it works on any day of the illness. If the fever has lasted five days or more and you only need antibodies, the Dengue Rapid Test (IgG/IgM) is a lower-cost option.
Why the platelet count matters
Dengue tests confirm the infection, but the complete blood count (CBC) is what doctors use to follow it. Dengue often lowers the platelet count and can raise the haematocrit (the proportion of red cells in the blood), which can signal fluid leaking from blood vessels. Doctors usually repeat the CBC every day or two during the critical phase, which often starts as the fever settles, around days 3 to 7. A single normal platelet count early on does not mean the illness will stay mild. Read more in our guide on why dengue causes low platelet counts.
Warning signs that need urgent care
Seek medical help straight away if any of these appear, especially when the fever is coming down:
- Severe stomach pain or persistent vomiting
- Bleeding from the nose or gums, or blood in vomit or stool
- Extreme tiredness, restlessness or confusion
- Cold, clammy skin or difficulty breathing
Do not wait for a test report if these signs appear. For the full list of symptoms, see dengue symptoms, causes and treatment.
When fever could be something else
Dengue, malaria, typhoid and chikungunya can all start with a sudden fever and body ache, and they are treated very differently. When the cause is not clear, a combined panel checks them together in one sample. The Jaanch Fever Panel Advanced covers dengue (NS1, IgM and IgG), malaria, typhoid and chikungunya with a CBC, CRP and ESR. You can read more about telling these fevers apart.
Dengue test price on SecondMedic
| Test | Includes | Price |
|---|---|---|
| Dengue Rapid Test (IgG/IgM) | Dengue IgG and IgM | Rs.363 |
| CBC (Hemogram 6-Part) | Platelets, haemoglobin, white cells and more | Rs.330 |
| Jaanch Dengue Profile | NS1, IgM and IgG (ELISA) with CBC | Rs.1,259 |
| Jaanch Fever Panel Advanced | Dengue, malaria, typhoid, chikungunya, CBC, CRP, ESR | Rs.1,680 |
Prices were checked at the time of writing and can change, so confirm the current price on each test page. Fasting is not needed for any of these tests. A trained phlebotomist collects the blood sample at home, and reports are shared digitally within 48 to 72 hours.
While you wait for the result
- Rest and drink plenty of fluids, such as water, oral rehydration solution, coconut water and soups.
- Paracetamol is generally used for fever. Avoid painkillers such as ibuprofen and aspirin unless a doctor advises them, because they can increase the risk of bleeding in dengue.
- Keep track of how many days you have had fever. It decides which test is useful and helps your doctor read the result.
If your report shows dengue or a falling platelet count, you can consult a doctor online to understand the next steps.
This article is for general information and does not replace medical advice. A doctor should interpret dengue test results together with your symptoms and examination.
