Widal Test

Widal Test is a method that may used to help diagnose enteric fever. The widal test is an agglutination test that detects the presence of serum agglutinins (H and O) in patients’ serum with typhoid and paratyphoid fever. The Widal Test reveals the presence of salmonella bacteria. Salmonella is an intestinal dieses. This fever does not touch normal fever but keeps going up and down. This fever is also called step ladder fever.

The correct way to diagnose enteric fever is blood or stool culture. If a culture test is not available, a serology test is called a widal test. Antibodies of salmonella are present in the patient’s serum. The widal test can also be done on the slide and can be seen in the test tube. The slide method is commonly used.

The traditional Widal test measures antibodies against flagellar (H) and somatic (O) antigens of the causative organism. In acute infection, the O antibody appears first, rising progressively, later falling and often disappearing within a few months. H antibody appears a little later but persists for longer. A rising or high O antibody titer generally indicates acute infection, whereas a raised H antibody helps to identify the type of enteric fever.

Is This Test Have Other Name

Widal Test, Typhoid Test, Enteric Fever Test,

How The Test Is Performed

A blood sample is needed.

Why Test Test Performed

Salmonella is an intestinal disease. Typhoid is a disease of the bowels. It is passed from one patient to another. This fever does not touch normal fever but keeps going up and down. This fever is also called step ladder fever. If you have symptoms are.

1. Vomiting
2. High-Grade Fever
3. Stomach Pain
4. Headache
5. Cough
6. Lose Motion
7. Rose Spot

Procedure Of Test

The patient’s serum is tested for O and H antibodies against the following antigen suspensions.
S. Typhi 0 antigen suspension
S. Typhi H antigen suspension
S. Paratyphi A 0 antigen suspension
S. Paratyphi A H antigen suspension
S. Paratyphi B 0 antigen suspension
S. Paratyphi B H antigen suspension
S. Paratyphi C 0 antigen suspension
S. Paratyphi C H antigen suspension

Procedure:

Draw the lick-shaped boxes below on a slide.

One drop in each box of O and H antigens. Now add 40 micro liter in the first box 30 micro liter in the second 20 micro liter in the third 10 micro liter fourth 5 micro liter in the fifth box and mix gently. Shake the slide for five minutes. Now you see which box the clumps appear in. If these clumps have appeared up to box 1:160 and beyond, the test result is positive. And if this test does not appear beyond 1:80 the test is negative.

Note:

The widal test is negative in the first week of illness.

What Does the Result Mean

If you performed the test once, The titer was low means 1:20 or 1:40, Then after a few days you performed the test again, and then the titer passed up to 1:80 or 1:160 which means the test is positive. If either O or H has a titer up to 1:160 the test is positive. And if the titer is below 1:160 then the results are negative. Some patients do not show any symptoms of typhoid yet they test positive. No need to worry about it. This test is not only specific for typhoid. Rather, a few organisms that resemble typhoid bacteria also test positive. For example joint diseases, after the typhoid vaccine, liver disease, kidney disease, etc.

In children’s, O usually comes first. In adults, H comes first positive.