The Widal test is a blood test used to detect antibody titres when typhoid or paratyphoid fever (collectively called enteric fever) is suspected. Antibody titres measure certain antibodies in the blood in reaction to antigens, or foreign substances, and show how the body is responding immunologically. The Widal test specifically identifies antibodies against the O and H antigens of Salmonella Typhi and the H antigens of Salmonella Paratyphi . Introduced by F. Widal in 1896, this test employs a suspension medium with killed Salmonella Typhi bacteria as the antigen to diagnose typhoid fever in patients with fever. Therefore, individuals showing symptoms of enteric fever may benefit from a Widal test.

Given its importance in diagnosing enteric fever, the Widal test is a vital tool for timely detection and treatment. If you are in Mumbai and experiencing enteric fever symptoms, consider taking a Widal test in Mumbai today.

Before booking the Widal test in Mumbai, consider the following factors:

Prerequisites

Fasting is not recommended for the Widal test.

Best Time to Get Tested

The Widal test can be taken at any time during the day.

Who Should Get a Widal Test

Individuals experiencing fever, headache, gastrointestinal issues (such as constipation, abdominal pain, or diarrhoea), and fatigue, especially if they have been in high-risk areas for typhoid or paratyphoid fever, should consider getting a Widal test.

Cautions Before Taking the Widal Test

For this test, there are no particular safety measures needed.

Typhoid bacteria usually have an incubation period of 6 to 14 days, though it can extend up to 30 days. This duration is the time between being infected with the bacteria and the start of symptoms. The incubation period for paratyphoid bacteria ranges from 1 to 10 days. Most of the time, symptoms get worse over the course of 3 to 4 days.

A doctor may request a Widal test if you exhibit symptoms of typhoid fever. Paratyphoid fever presents similar, but less severe, symptoms. These signs and symptoms include:

• High fever or chills

• Extreme fatigue

• Feeling unwell, weak, or sick

• Headache

• Red rash on the chest and abdomen

• Pain in the abdomen

• Sweating

• Constipation

• Diarrhoea

• Blood in the stool

• Weight loss

• Sore throat and persistent cough

• Bleeding from the nose

• Decreased heart rate

• Loss of appetite

• Confusion or hallucinations

• Difficulty in concentrating

• Poisoning of blood

• Enlarged spleen or liver

Keep in mind that even those vaccinated against typhoid are not completely immune, as 20–50% of vaccinated individuals may still contract the disease if exposed.

A Widal test may be recommended for individuals at increased risk of typhoid, including:

• Young children, as they are more vulnerable than adults to certain illnesses.

• People who have come into proximity with an infected individual.

• Travellers to regions where typhoid and paratyphoid are common (such as India, Bangladesh, the Middle East, and Africa).

Below is a breakdown of the results of the Widal test:

Interpretation

A titre below 1:80 is deemed negative, indicating no infection in the patient.

Titres of 1:80 or higher are generally considered positive, though this threshold can differ across populations and regions. A rising titre, seen through two or more samples taken at 4- to 6-day intervals after disease onset, holds more significance than a single high titre. Test results should be interpreted in conjunction with the patient’s medical history to confirm a diagnosis.

Limitations

Patients vaccinated against typhoid may exhibit elevated antibody titres, potentially resulting in false-positive outcomes. Similarly, individuals with previous infections or immunisations may also have misleading results.

Agglutinins typically appear in the blood by the end of the first week of infection, so samples taken earlier might return negative results.

While the serological findings of this test are important, they should not replace culture-based methods for identifying the causative organisms. Efforts should be made to recover and identify the pathogens through culture and biochemical tests.