Which of the following is not correctly matched ?

Options

A. Dengue fever-Arbovirus
B. Plague-Yersinia pestis
C. Syphilis-Trichuris trichura
D. Sleeping Sickness-Tryanosoma gambiense

Answer

To determine which disease is not correctly matched with its causal organism, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the First Option: Dengue Fever**
- **Causal Organism**: Arbovirus
- **Analysis**: Dengue fever is indeed caused by the arbovirus, which is transmitted by mosquitoes.
- **Conclusion**: This option is correctly matched.

2. **Identify the Second Option: Plague**
- **Causal Organism**: Yersinia pestis
- **Analysis**: Plague is caused by the bacterium Yersinia pestis, which is an enterobacterium.
- **Conclusion**: This option is correctly matched.

3. **Identify the Third Option: Syphilis**
- **Causal Organism**: Trichuris trichura
- **Analysis**: Syphilis is a sexually transmitted disease caused by the bacterium Treponema pallidum, not Trichuris trichura, which is a parasitic worm causing a different disease (whipworm infection).
- **Conclusion**: This option is incorrectly matched.

4. **Identify the Fourth Option: Sleeping Sickness**
- **Causal Organism**: Trypanosoma gambiense
- **Analysis**: Sleeping sickness is caused by the protozoan parasite Trypanosoma gambiense.
- **Conclusion**: This option is correctly matched.

### Final Answer:
The option that is not correctly matched is **Syphilis, which is incorrectly associated with Trichuris trichura**.