A communicable disease, which if not controlled immediately is 100% fatal

Options

A. Syphilis
B. kala-azar
C. Filariasis
D. Hydrophobia

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a communicable disease that is 100% fatal if not controlled immediately. This indicates that the disease must have a very high mortality rate if treatment is delayed.

2. **Analyzing the Options**:
- **A. Syphilis**: This is a sexually transmitted infection caused by the bacterium Treponema pallidum. While it can have serious health consequences if untreated, it is not 100% fatal.
- **B. Kala Azar**: Also known as visceral leishmaniasis, this disease is caused by the Leishmania parasite and can be fatal if untreated, but it does not have a 100% fatality rate.
- **C. Filariasis**: This is caused by parasitic worms and leads to conditions like elephantiasis. It is not immediately fatal and can be treated effectively.
- **D. Hydrophobia**: This is another name for rabies, a viral disease that affects the brain and is transmitted through bites from infected animals. If not treated immediately after exposure, rabies is almost always fatal.

3. **Identifying the Correct Answer**: Based on the analysis, the only disease that fits the criteria of being communicable and having a 100% fatality rate if not treated immediately is hydrophobia (rabies).

4. **Conclusion**: Therefore, the answer to the question is option D, hydrophobia.

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