Which of the following diseases is diagnosed by WIDAL test?

Options

A. amoebic dysentery
B. typhoid
C. tuberculosis
D. Pneumonia

Answer

**Step-by-Step Solution:**

1. **Understanding the Widal Test**: The Widal test is a serological test used to diagnose typhoid fever. It detects the presence of specific antibodies (O and H antigens) against the bacteria Salmonella typhi in the patient's serum.

2. **Identifying the Disease**: Among the diseases listed, we need to identify which one is associated with the Widal test. The primary disease diagnosed using this test is typhoid fever.

3. **Confirming the Diagnosis**: The Widal test is not only used for diagnosis but also helps in confirming the presence of typhoid fever. It is important to note that while the test can indicate typhoid, it may not be definitive in all cases due to potential cross-reactivity with other infections.

4. **Conclusion**: Based on the information about the Widal test and its association with typhoid fever, we conclude that the disease diagnosed by the Widal test is typhoid.

**Final Answer**: The disease diagnosed by the Widal test is typhoid fever.

---