Widal Test (Slide Test)
Antibody titres against typhoid and paratyphoid. Widely used, but only meaningful after the first week and against a baseline
Also known as Widal, Typhoid test, Typhoid antibodies, Widal Test, Widal Test (Slide Method)
₹145/-Free collection on orders above ₹500/-
- Reports within
- 8 hours
- Parameter included
- 01see list
- Sample
- Blood
- Fasting
- Not needed
- Measures
- Antibody titres against Salmonella typhi (O and H) and Salmonella paratyphi A and B (H)
- Identifies
- Typhoid and paratyphoid fever after the first week of illness
Collected at home
A trained phlebotomist visits at a time you pick, from the next hour
Sealed single-use kit
Opened in front of you, and carried to the lab under controlled conditions
Report within 8 hours
On WhatsApp and email, with any value outside the normal range highlighted
What is the Widal test?
The Widal test looks for antibodies your body makes against the bacteria that cause typhoid and paratyphoid fever, together called enteric fever. It reports four titres: O and H against Salmonella typhi, and AH and BH against Salmonella paratyphi A and B. A titre is the highest dilution of your blood that still reacts, written as 1:40, 1:80 and so on. Higher means more antibody.
The test is widely used in India, but it has a clear limit. Antibodies take a week to appear, so a sample in the first few days of fever is often negative even when typhoid is present. And because typhoid is common here and many people are vaccinated, a modest titre can be left over from the past. A doctor reads the result against how many days you have had fever, and may repeat it a week later to see if the titre is rising. A rising titre means much more than a single high one. A blood culture remains the surer way to confirm typhoid in the first week.
No fasting is needed. The sample is collected at home and the report arrives in 8 hours.
Widal parameters1 measured
Widal (S. typhi O / H, paratyphi AH / BH)
Below 1:80
Measures antibodies against typhoid and paratyphoid bacteria, rising titres over a week or so suggesting enteric fever, though past exposure can also raise them
Reference ranges are the lab's defaults for adults and are printed on the report beside every value
How to prepare
- No fasting is needed.
- Note the day your fever started and tell the phlebotomist, since the result depends on it.
- Tell the phlebotomist if you have had a typhoid vaccine or typhoid infection in the past, as both raise the titres.
- If possible, get the sample before starting antibiotics, and tell your doctor if you already have.
Who should take it
Anyone with fever lasting more than five days, particularly a fever that rises in steps, with headache, weakness, abdominal pain, constipation or diarrhoea and poor appetite. People whose dengue and malaria tests are negative and whose fever has entered its second week. Family members and close contacts of someone with confirmed typhoid. Children and young adults, who get typhoid most often. Anyone who has recently eaten outside food or drunk unfiltered water and now has fever. It is most useful from the seventh day of fever onwards; before that, a blood culture is better.
Before the visit
Tell your doctor about typhoid vaccination, past typhoid, and any antibiotics already taken, which can blunt the antibody response. Malaria, dengue and some other infections occasionally cause false positives. A negative Widal in the first week does not rule out typhoid.
Why take the Widal test?
- Fever that will not break: a fever that climbs day by day for more than five to seven days, with headache and loss of appetite, is typical of typhoid.
- Stomach symptoms with fever: abdominal pain, constipation or diarrhoea, and a coated tongue alongside fever point to enteric fever.
- Other fevers ruled out: if dengue and malaria tests are negative and the fever continues into the second week, this is the next step.
- Contact or outside food: a family member with typhoid, or recent street food or unsafe water, raises the likelihood.
- Confirming a rising titre: a second sample a week after the first shows whether antibody levels are climbing, which is far more meaningful than one reading.
Questions about the Widal test
What is the Widal test used for?
It looks for antibodies against the bacteria that cause typhoid and paratyphoid fever. It is ordered when a fever has lasted a week, particularly with headache, abdominal pain, constipation or diarrhoea, and when dengue and malaria have been ruled out.
Do I need to fast for the Widal test?
No fasting is needed. Note the day your fever started, tell the phlebotomist about any typhoid vaccine or past typhoid, and mention any antibiotics you have already taken.
What sample is taken and how does home collection work?
A small blood sample from the arm. A trained phlebotomist comes to your home with a sealed single-use kit and takes the sample to the lab, where the serum is tested against the four antigens.
What is a normal Widal result?
The report gives four titres: S. typhi O and H, and S. paratyphi AH and BH. A titre below 1:80 for each is reported as negative. Titres are written as dilutions such as 1:40, 1:80 or 1:160, and higher means more antibody.
What does a positive Widal titre mean?
A titre of 1:80 or above suggests recent exposure to typhoid or paratyphoid, but on its own it is not proof, because past infection and vaccination also raise titres. A titre that rises between two samples taken a week apart is much stronger evidence. Your doctor reads it with your symptoms and the day of fever.
Who should get a Widal test and when?
Anyone whose fever has lasted more than five to seven days, especially with headache, weakness, poor appetite and stomach symptoms, and close contacts of someone with typhoid. It is most useful from the seventh day of fever; before that the antibodies have often not appeared.
How long does the Widal report take?
The report reaches your WhatsApp and email in 8 hours from collection. If your doctor wants a second titre a week later to see whether it is rising, book the repeat collection for the same time of day.
Can the Widal test be wrong?
Yes, in both directions. It is often negative in the first week of typhoid because antibodies take time to appear, and it can be positive in someone who was vaccinated or had typhoid years ago. A blood culture is the surer test early on. That is why doctors ask for the day of fever and sometimes repeat the test.
I had typhoid last year. Will my Widal still be positive?
Quite possibly. Titres can stay raised for a year or more after infection or vaccination, so a single positive result means little. If you have a new fever, your doctor will look for a titre that is rising between two samples, or use a blood culture instead.
Commonly tested together
Often on the same prescription
₹400/-₹500/-20% off
What happens after you book
- A phlebotomist is assigned and reaches you in your chosen slot, as soon as the next hour
- The sample is collected with a sealed single-use kit and moved on a cold chain
- The report lands on WhatsApp and email within 8 hours