Which of the following diseases affects the immune system directly?

Options

A. Cholera
B. TB
C. Tetanus
D. AIDS

Answer

To determine which disease affects the immune system directly, we can analyze the given options step by step.

### Step 1: Identify the diseases listed in the options.
- The diseases mentioned are Cholera, Tuberculosis (TB), Tetanus, and AIDS.

### Step 2: Understand the nature of each disease.
- **Cholera**: Caused by the bacterium Vibrio cholerae. It primarily affects the intestines and leads to severe diarrhea and dehydration.
- **Tuberculosis (TB)**: Caused by the bacterium Mycobacterium tuberculosis. It primarily affects the lungs but can also impact other parts of the body.
- **Tetanus**: Caused by the bacterium Clostridium tetani. It affects the nervous system and leads to muscle stiffness and spasms.
- **AIDS**: Stands for Acquired Immunodeficiency Syndrome, caused by the Human Immunodeficiency Virus (HIV). This virus directly attacks the immune system.

### Step 3: Analyze how each disease interacts with the immune system.
- **Cholera, TB, and Tetanus**: While these diseases are caused by bacteria and the immune system responds to them, they do not directly impair the immune system. Instead, the immune system works to fight off these infections.
- **AIDS**: This disease is unique because HIV directly attacks and weakens the immune system, specifically targeting CD4 T cells, which are crucial for immune response.

### Step 4: Conclusion
Based on the analysis, the disease that directly affects the immune system is **AIDS**.

### Final Answer
The disease that affects the immune system directly is **AIDS**.

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