A person has developed interferons in his body. He seems to carry an infection of

Options

A. tetanus
B. malaria
C. measles
D. typhoid.

Explanation

**Step-by-Step Solution:**

1. **Understanding Interferons**: Interferons are a group of signaling proteins produced by host cells in response to viral infections. They play a crucial role in the immune response by signaling neighboring cells to enhance their antiviral defenses.

2. **Mechanism of Action**: When a virus enters the body, it triggers the immune system, leading to the activation of white blood cells. These cells release interferons, which help to inhibit the replication of viruses and boost the overall immune response.

3. **Function of Interferons**: Interferons do not directly kill viruses. Instead, they interfere with the production of new viruses and regulate genes that help in fighting viral infections. This makes them essential in the body's defense against viral pathogens.

4. **Analyzing the Options**:
- **Option 1: Tetanus** - This is caused by a bacterium (Clostridium tetani), not a virus. Therefore, interferons would not be produced in response to this infection.
- **Option 2: Malaria** - This disease is caused by the Plasmodium parasite, which is neither a virus nor triggers interferon production.
- **Option 3: Measles** - This is a viral infection, and it is known that interferons are produced in response to viral infections. Hence, this is a likely correct answer.
- **Option 4: Typhoid** - Caused by the bacterium Salmonella typhi, this infection would not lead to the production of interferons.

5. **Conclusion**: Based on the analysis, the correct answer is **Option 3: Measles**, as it is a viral infection that would lead to the production of interferons in the body.

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