What is Widal test normal range?

Conclusion: In case of singular Widal test, baseline values for the normal range was found to be 1:20 – 1:80 for all the antigens (TO, TH, AO, AH, BO, BH), except BH, for which it was 1:20-1:40.

How do I read my typhoid test results?

The Widal test is positive

1. if “O” antigen titer is >1:160 = active infection.
2. If the “H” antigen titer is >1:160, it indicates past infection or in immunized persons.
3. A fourfold increase in the titer (e.g., from 1:40 to 1:160) is diagnostic.

What is positive and negative in Widal test?

So a negative Widal test result has a good predictive value for the absence of the disease but a positive result would have a low predictive value for the presence of typhoid fever [9].

What is a positive Widal test?

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 ah in Widal test?

The antigens used in the test are “H” and “O” antigens of Salmonella Typhi and “H” antigen of S. Paratyphi. The paratyphoid “O” antigen are not employed as they cross react with typhoid “O” antigen due to the sharing of factor 12. “O” antigen is a somatic antigen and “H” antigen is flagellar antigen.

What is Widal test positive?

Is it Typhoid to positive 1 80?

Salmonella typhi H and O titres greater than or equal to 1:160 occurred in respectively 82% and 58% of typhoid fever patients; only 4% of healthy individuals and 8% of non-typhoid patients had Widal titres greater than or equal to 1:80.

How do I know my Widal test is 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.

What titre is positive for typhoid?

Taking antibody Titer of ≥1:80 for O and ≥1:160 for H antigens as cutoff values to indicate recent typhoid infection (positive titer), 25 (4.9%) and 15 (2.9%) patients had results indicative of recent typhoid infection by O and H antigens, respectively.

What does my Widal test indicate?

The Widal test usually detects antibodies against flagellar and somatic antigens of the causative organisms of enteric fever, Salmonella typhi. 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.

What does This Widal test results indicate?

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.

What is the procedure for Widal test?

Procedure : Bring all reagents to room temperature and mix well. Dispense one drop of saline into the first reaction circle and then place 5, 10, 20, 40, 80 ul of the test sample on the remaining circles. Add a drop of the antigen, which showed agglutination with the test sample in the screening (qualitative) method, to each circle.

What does Widal test stand for?

In 1896 and named after its inventor, Georges-Fernand Widal, is an indirect agglutination 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.