WIDAL test is used for the detection of

Options

A. Disease caused by a protozoan called Trichomonas
B. Disease caused by a rod shaped bacterium called Salmonella typhi
C. Disease caused by a spherical bacterium called N. gonorrhoea.
D. Disease caused by a spiral bacterium called Treponema pallidum

Answer

**Step-by-Step Solution:**

1. **Understanding the Widal Test**: The Widal test is a serological test used to detect the presence of specific antibodies in the blood that are produced in response to the infection caused by Salmonella typhi, the bacterium responsible for typhoid fever.

2. **Identifying the Pathogen**: The primary pathogen associated with typhoid fever is Salmonella typhi. This bacterium is a type of Gram-negative bacteria that can cause severe gastrointestinal illness.

3. **Analyzing Other Options**:
- **Trichomonas**: This is a protozoan parasite that causes trichomoniasis, which is typically diagnosed through urine tests or vaginal swabs, not the Widal test.
- **Salmonella typhi**: This is indeed the correct answer as it is the pathogen detected by the Widal test.
- **N. gonorrhea**: This bacterium causes gonorrhea, a sexually transmitted infection, and is diagnosed using nucleic acid amplification tests (NAAT), not the Widal test.
- **Treponema**: This is the bacterium that causes syphilis, which is tested using the Rapid Plasma Reagin (RPR) test, not the Widal test.

4. **Conclusion**: Based on the analysis, the Widal test is specifically used for the detection of antibodies against Salmonella typhi, confirming that the correct answer is indeed Salmonella typhi.

**Final Answer**: The Widal test is used for the detection of Salmonella typhi.

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