A comparative study of Widal test with blood culture in the diagnosis of typhoid fever in febrile patients


Andualem G,  Abebe T,  Kebede N,  Gebre-Selassie S,  Mihret A,  and Alemayehu H.


Background: Typhoid fever is a major health problem in developing countries and its diagnosis on clinical ground is difficult. Diagnosis in developing countries including Ethiopia is mostly done by
Widal test. However, the value of the test has been debated. Hence, evaluating the result of
this test is necessary for correct interpretation of the result. The main aim of this study was to
compare the result of Widal test and blood culture in the diagnosis of typhoid fever in febrile

Methods: Blood samples were collected from 270 febrile patients with symptoms clinically similar to
typhoid fever and visiting St. Paul’s General Specialized Hospitals from mid December 2010
to March 2011. Blood culture was used to isolate S.typhi and S.paratyphi. Slide agglutination
test and tube agglutination tests were used for the determination of antibody titer. An
antibody titer of ≥1:80 for anti TO and ≥1:160 for anti TH were taken as a cut of value to
indicate recent infection of typhoid fever.

Results: One hundred and eighty six (68.9%) participants were females and eighty four (31.1%) were
males. 7 (2.6%) cases of S. typhi and 4 (1.5%) cases of S. paratyphi were identified with the
total prevalence of typhoid fever 4.1%. The total number of patients who have indicative of
recent infection by either of O and H antigens Widal test is 88 (32.6%). The sensitivity,
specificity, Positive predictive Value and Negative predictive Value of Widal test were
71.4%, 68.44%, 5.7% and 98.9% respectively.

Conclusions: Widal test has a low sensitivity, specificity and PPV, but it has good NPV which indicates
that negative Widal test result have a good indication for the absence of the disease.


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