A Prospective Comparative Study of Semi-Quantitative Slide Widal test& Quantitative Tube Widal test

Authors

Dr Nidhi K Sood, Dr Manisha M Jain, Dr Sachin Patel, Dr Asha Mandalia, Dr H K Bhavsar.

Abstract

Objective: The diagnosis of enteric fever currently depends upon the isolation of Salmonella from a patient, most commonly by blood culture. This facility is not available in many areas where the disease is endemic. The Widal agglutination test which demonstrates the presence of somatic (O) and flagellar (H) agglutinins to Salmonella in the patient’s serum using O and H antigen suspension is one of the most utilized diagnostic tests for typhoid fever in developing countries. In the recent past, a rapid slide test was developed which is now the most commonly used technique in local laboratories because of its convenience. The semi-quantitative slide test provides an approximation to the tube test titre. The present study was an attempt to compare the results of semi-quantitative slide agglutination with the quantitative tube method to ascertain any significant difference between two methods.

Material and Methods: 300 precollected blood samples of OPD patients were collected over a period of 4 months and subjected to semi-quantitative rapid slide and quantitative tube Widal tests using commercially available Salmonella antigen test kits.

Results: From the 300 samples studied, 17(5.7%) serum samples were positive by slide test method while 25(8.7%) seropositive by Tube test method. Present study shows, slight difference in the results obtained by the two methods of Widal test.

Conclusion: The Tube Widal test is more sensitive and specific than slide Widal test, especially for rule out prozone phenomena, but slide Widal agglutination test is found to good alternative screening test because less time consuming, easy to perform, cost effective and can be applied in resource poor nations. There is an urgent need for the rational design and evaluation of effective and appropriate diagnostics for typhoid fever.

 

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