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What is slide method in Widal test?

What is slide method in Widal test?

Widal test (Slide agglutination) is a blood test which detects Enteric fever (Typhoid fever and Paratyphoid fever). Enteric fever is a systemic infection caused by bacteria, mainly because of the ingestion of contaminated food or water. This test is performed using the slide agglutination method.

How do you perform a widal slide test?

Procedure of Widal Test

  1. Place one drop of positive control on one reaction circles of the slide.
  2. Pipette one drop of Isotonic saline on the next reaction cirlcle.
  3. Pipette one drop of the patient serum tobe tested onto the remaining four reaction circles.

What are the two types of Widal test?

Widal test procedure involves the serum agglutination test to detect typhoid fever. Patients who are suffering from enteric fever will carry homologous antibodies in the serum. The slide method and the tube method are the two types of Widal test procedures.

What is Widal test and how it is done?

The traditional Widal test measures antibodies against flagellar (H) and somatic (O) antigens of the causative organism. In acute infection, 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.

What is slide agglutination?

Slide Agglutination. The slide agglutination technique is used to determine which of several bacteria agglutinates a preparation of selected antibodies. Emulsions of unknown bacteria are mixed with drops of known antibodies on a micro- scope slide, and the mixture is observed for agglutination.

What type of test is Widal test agglutination?

Widal agglutination was introduced as a serologic technique to aid in diagnosis of typhoid fever. The test was based on demonstrating the presence of agglutinin (antibody) in the serum of an infected patient, against the H (flagellar) and O (somatic) antigens ofSalmonella typhi.

When is Widal test positive?

The Widal test is positive if TO antigen titer is more than 1:160 in an active infection, or if TH antigen titer is more than 1:160 in past infection or in immunized persons. A single Widal test is of little clinical relevance especially in endemic areas such as Indian subcontinent, Africa and South-east Asia.

What is the use of widal test?

The Widal test is one method that may be used to help make a presumptive diagnosis of enteric fever, also known as typhoid fever.

What is the full definition of widal test?

Medical Definition of Widal test : a test for detecting typhoid fever and other salmonella infections using the Widal reaction — compare agglutination test.

Which is the best method for the Widal test?

The Widal test can be conducted in two ways : Slide agglutination Widal test 1. Qualitative Slide Test 2. Quantitative Slide Test Tube agglutination Widal test Tube agglutination has more accuracy as compared to the slide agglutination technique. However, A slide widal test is more popular among diagnostic laboratories as it gives rapid results.

Can you use Widal test for slide agglutination?

Widal test is still a common way of diagnosing enteric fever cases in several countries. Although tube agglutination is the standard, some manufacturers have adapted it for slide agglutination. This video shows qualitative as well as quantitative test on a kit that can be used for both slide as well as tube agglutination.

When to use Widal test for typhoid fever?

The Widal test has been in use for more than a century as an aid in the diagnosis of typhoid fever. It measures agglutinating antibody levels against O and H antigens. The Widal test is positive after the tenth day of the disease and may be false positive if an individual previously received a TAB vaccine.

How to do the Widal antigen suspension test?

1 Place one drop of positive control on one reaction circles of the slide. 2 Pipette one drop of Isotonic saline on the next reaction cirlcle. 3 Pipette one drop of the patient serum to be tested onto the remaining four reaction circles. 4 Add one drop of Widal TEST antigen suspension ‘H’ to the first two reaction circles.

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