Widal test is used for susceptibility of

Options

A. Pneumonia
B. Malaria
C. typhoid
D. cholera

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 (agglutinins) in the blood that respond to the bacteria Salmonella typhi, which causes typhoid fever.

2. **Identifying the Disease**: The question asks for the disease for which the Widal test is used to assess susceptibility. The primary disease diagnosed using the Widal test is typhoid fever.

3. **Mechanism of the Test**: The Widal test works by identifying agglutinins (antibodies) against the O and H antigens of Salmonella typhi in the patient's serum. If these antibodies are present, it indicates that the person has been exposed to the bacteria and may have typhoid fever.

4. **Evaluating the Options**: The options provided in the question likely include:
- A) Pneumonia
- B) Malaria
- C) Cholera
- D) Typhoid

Among these options, the correct answer is D) Typhoid, as the Widal test specifically detects antibodies related to this disease.

5. **Conclusion**: Therefore, the Widal test is used for the susceptibility of typhoid fever, which is caused by Salmonella typhi.