Widal Test Report: Normal Range & How to Read It
A Widal test looks for antibodies against the bacteria that cause typhoid fever. Each result is printed as a titre, such as 1:80 or 1:160.
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What a Widal test checks
Typhi O (TO)
Antibodies against the O antigen of Salmonella Typhi.
Typhi H (TH)
Antibodies against the H antigen of Salmonella Typhi.
Paratyphi A and B (AH, BH)
Antibodies against the H antigens of Paratyphi A and B.
Widal test normal titre
Labs differ a little. Always compare with the range printed on your report.
| Test | Usual result | Unit | What it tells you |
|---|---|---|---|
| Widal test | |||
| S. Typhi O (TO) | Below 1:80 | titre | A higher titre can point to a recent infection. |
| S. Typhi H (TH) | Below 1:80 | titre | Can stay raised for months after a vaccine. |
| S. Paratyphi AH | Below 1:80 | titre | Antibodies against Paratyphi A. |
| S. Paratyphi BH | Below 1:80 | titre | Antibodies against Paratyphi B. |
| Typhidot (often done with it) | |||
| Typhidot IgM | Negative | Positive points to a recent infection. | |
| Typhidot IgG | Negative | Can stay positive after a past infection. | |
Ranges from the NirogGyan biomarker library. Updated .
What a Widal report looks like
The same results in the usual lab layout, and as a NirogGyan Smart Report.
Numbers and ranges in rows
Each value on our report slider
How to read your Widal report
Check the method
Slide and tube methods can give different titres. Note which one your lab used.
Find each titre
Each row shows the highest dilution where antibodies were still seen.
Compare with the cut-off
Your report prints the titre your lab treats as significant.
Read it with your fever
Your doctor reads the titre with how long you have had fever, and decides what it means.
Widal report questions
What is a normal Widal test result?
Our biomarker library uses negative, or a titre below 1:80. Cut-offs differ between labs and regions, so read the cut-off printed on your report.
What do TO, TH, AH and BH mean?
TO and TH are antibodies against the O and H antigens of Salmonella Typhi. AH and BH are antibodies against the H antigens of Paratyphi A and B.
Does a positive Widal test confirm typhoid?
A positive Widal test supports typhoid, and doctors often confirm it with a blood culture or other tests. They also look at how long you have had fever.
When is the Widal test most useful?
Usually after the first week of fever, when antibodies have had time to rise. A test done too early can read low.
Can a Widal test stay positive after typhoid?
Yes. Antibodies can stay for months after an infection or a typhoid vaccine, which is why one result is read with your symptoms.
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Upload your reportThis page explains how to read a lab report. It does not replace advice from your doctor. All sample values are made up.