Comparative evaluation of diagnostic efficacy of widal slide. We also evaluated the agreement between widal, stool and blood culture. Ppv and negative predictive value npv were calculated. Get your query answered 247 with expert advice and. Widal test is an agglutination test which detects the presence of serum agglutinins h and o in patients serum with typhoid and paratyphoid fever. During infection with salmonella, the human body reacts to the antigenic stimulus and antibodies are produced. Also known as enteric fever, typhoid is rare in the united states and other developed countries but is still an ongoing threat to those who live or visit developing nations. Although the test is no longer commonly performed in the united states or other developed countries, it is still in use in many emerging nations where enteric fever is endemic and limited resources require the use of. None of the serum samples of the typhoid fever patients showed. The tube agglutination, allows reliable results, but its realization is longer and. Widal slide and tube test principle and result interpretation. Widal test is an agglutination test which detects the presence of serum agglutinins h and o in patients serum with typhoid and paratyphoid.
Limitation of widal test the widal test is time consuming and often times when diagnosis is reached it is too late to start an antibiotic regimen. The titres increase during second, third and fourth week after which it gradually declines. Diagnosis and treatment of typhoid fever and associated. Similarly, when the 2 liters were considered to gether, either o or. Test results need to be interpreted carefully to account for any history of enteric fever. Microbiology 321 k salmonella typhoid lab diagnosis widal test 2 duration. Pdf typhoid and paratyphoid fever is still an existing health. Widal test results showed marked discrepancies using different widal brands. The widal tube agglutination test, which is almost 100 years old, has been widely used in the serologic diagnosis of typhoid fever in turkey. Widal test in diagnosis of typhoid fever in turkey. Based on our results, the slide widal test is not helpful in the diagnosis of. The widal test was developed over a century ago and remains one of the worlds most widely used diagnostic tests but suffers from significant limitations in its sensitivity and specificity, as well as reliability. Enteric fever refers to typhoid and paratyphoid caused by salmonella typhi and salmonella paratyphi a, b, c respectively.
Over 100 years since its introduction as a serologic means of detecting the presence of typhoid fever, the widal test continues to be plagued with controversies involving the quality of the antigens used and interpretation of the result, particularly in endemic areas. Widal test definition at, a free online dictionary with pronunciation, synonyms and translation. The subjects were all adults 18 years of age and were divided into four groups. Salmonella typhi rod shaped, flagellated, aerobic, gram ve bacilli. Technique and interpretation of the weilfelix test in. Based on the manufacturers manual, an antibody titer of. Preparation for widal test slide agglutination test h suspension of bacteria is prepared by adding 0. During acute typhoid fever, o agglutinins can usually be detected 68 days after the onset of fever and h agglutinins after 1012 days. The slide agglutination test can be used as screening tool and the positive results should be confirmed by the tube agglutination test. Interpretation of widal test pdf new pdf download service. In spite of several limitation many physicians depend on widal test.
Significance and value of the widal test in the diagnosis of. Two rapid kits, typhidot and tubex, demonstrated promising results. Widal test article about widal test by the free dictionary. January 12, 2020 by sagar aryal widal test objective, principle, procedure, types, results, advantages and limitations. Widal test introduction, principle, procedure, interpretation and. Widal test is a serological test which is used for the diagnosis of enteric fever or typhoid fever. A single widal test is not sufficient for correct results and at least two tests should be conducted. Widal test is known to be one of the most reliable serological tests for enteric fever or undulant fever by bacteria causing typhoid and malaria where the serum is mixed with a specific antibody. The antibody titer is taken as the highest dilution of serum in which agglutination occurs. Pdf interpretation of widal test a short presentation. Interpretation of the widal test in the diagnosis of. The bacterium is spread due to intake of food or water contaminated with the faeces of an infected person poor hygienic conditions.
Widal test, introduction and procedure in lab youtube. The widal test is one method that may be used to help make a presumptive diagnosis of enteric fever, also known as typhoid fever. The oxidase test is helpful to contribute in the identification of neisseria, vibrio, pseudomonas, brucella, and pasteurella spp, all of which produce the oxidase enzyme. It helps to detect presence of salmonella antibodies in a patients serum. A single positive is less significant than the rising antibody titre, since rising titre is considered to be a definite evidence of infection. Two different types of the curve of ox19 agglutinin formation are found in patients suffering from louseborne typhus. The widal test was insensitive and displayed interoperator vari ability. Interpretation of widal test a short presentation to stimulate a long discussion. Sensitivity and specificity of widal test vary from place to place.
The widal test can be performed in the tube and on slide 10. Widal test introduction, principle, procedure, interpretation and limitation. This was a crosssectional study conducted between june and september 2018, in three regional. Process of reading widal test report is quite comfortable where you will have to check for the highest dilution of the serum. In interpreting widal test results, it is important that there should be close communication between the physician requesting the test and the laboratory, since. It is conclude, that even today, the widal test remains one of the best, easily accessible, cheap and simple method for the diagnosis of typhoid fever. We set an experiment to determine the diagnostic performance of the widal test and stool culture in typhoidsuspected cases attending tertiary hospitals in dar es salaam, tanzania using blood culture as a golden standard. Introduction, principle, procedure, result interpretation, applications and limitations introduction.
Oxidase test is supreme supportive in the screening colonies socalled of being one of the enterobacteriaceae group all gram negative bacteria. The value of a widal test in diagnosing typhoid fever was assessed in children aged between 1 and 10 years in bangladesh. Widal originally described the test to diagnose salmonella enterica serotype paratyphi b infection patients infected with s. The test may be negative in early part of first week.
Does a positive widal test indicate that i am a typhoid. Widal test is a common agglutination test employed in the serological diagnosis of enteric fever. Introduction of widal test widal test is a serological test that is done for the diagnosis of typhoid fever caused by salmonella organism. In cases of salmonella infection, it is a demonstration of the presence of o.
Clinicians in turkey generally consider a titer of. To determine whether a person is a carrier or not, the test should detect for the presence of antibodies against another antigen called as vi. Hence, establishing and updating the baseline widal titre for a particular area are an important factor in the proper interpretation of the widal test. On receipt, store the antigen solutions and test sample at 28 oc. The widal test was developed by georges ferdinand widal in 1896. The test was done on sera specimens from 300 healthy school children, 100 patients with nontyphoidal febrile illness and 150 bacteriologically proven cases of typhoid fever.
Hence a widal test performed early in the first week may give negative results. Performance of widal test and stool culture in the diagnosis of. Sensitivity, specificity, positive predictive value. Widal test is used for the diagnosis of enteric fever. In 1896 and named after its inventor, georgesfernand widal, is a presumptive serological test. Based on the manufacturer manual, an antibody titre of 1.
The world health organization who has said that due to the various factors that can influence the results of a widal test, it is best not to rely. Evaluation of rapid diagnostic tests for typhoid fever journal of. When facilities for culturing are not available, the widal test is the reliable and can be of value in. Until another easy, affordable, and reliable option is developed, however, the widal test will probably continue being used in those regions with limited. The type of agglutination seen with o reactions is granular while that seen with h reactions. Understanding the widal test typhoid fever is a life threatening condition that attacks over 21 million people around the world each year. The widal test usually detects antibodies against flagellar and somatic antigens of the causative organisms of enteric fever, salmonella typhi. When facilities for culturing are not available, the widal test is the reliable and can be of value in the. Typhoid fever is significant cause of morbidity across the world, with an estimated. Thus, assessment of the widal baseline titre for healthy individuals in a specific geographical area should be performed from time to time. Timing of test is important, as antibodies begin to arise during end of first week.
The salmonella antibody starts appearing in serum at the end of the first week and rises sharply during the 3rd week of endemic fever. Widal test medical definition merriamwebster medical. Pdf interpretation of widal test a short presentation to stimulate a. The two types of reaction curve are related to the clinical course of the disease and form the basis for the interpretation of the results of the weilfelix test. Performance of widal test and stool culture in the. But please keep in mind widal test should be done only after 7 days of fever. Comparative study of widal test against stool culture for. When the test sample is treated with colored and attenuated salmonella antigen suspensions, the antibodies present in the sample react with the antigen suspension to produce a clearly visible agglutination visible to the naked eye. Widal test is an old diagnostic test obsolete in developed countries, but the most common test in developing countries like india, pakistan etc. This is the first study done in turkey to assess the significance of the widal test. In 1896 and named after its inventor, georgesfernand widal, is a presumptive serological test for enteric fever or undulant fever whereby bacteria causing typhoid fever is mixed with a serum containing specific antibodies obtained from an infected individual. The widal test is reported by giving the titer for both o and h antibodies. Widal tube test kit should be used according to the kit.
The world health organization who says that because of the variety of factors that can sway the results of a widal test interpretation, it recommends the use of cultures whenever possible. The antibodies develop at the end of the first week and the titres rise during 2 nd, 3 rd and 4 th week, after which they slowly decrease. Widal test interpretation, normal values, procedure. Principle, procedure, result interpretation and limitations by editorial team on january 11, 2020 in bacteriology, microbiology salmonella typhi and salmonella paratyphi a, b and c cause enteric fever typhoid and paratyphoid in human.