Filariasis is due to infection of

Options

A. Nematode
B. Leech
C. Bed Bug
D. Flea

Answer

**Step-by-Step Solution:**

1. **Understanding Filariasis**: Filariasis is a parasitic disease that affects humans. It is important to identify the causative agent of this disease.

2. **Identifying the Causative Agent**: The disease is caused by infection with parasitic worms. Specifically, these are roundworms that belong to the group known as nematodes.

3. **Recognizing the Transmission Vector**: The primary vector for the transmission of filariasis is the female Culex mosquito. This mosquito carries the larvae of the filarial worms and transmits them to humans through bites.

4. **Effects of the Infection**: Once inside the human body, the filarial worms primarily affect the lymphatic system, leading to severe complications such as lymphedema and elephantiasis.

5. **Evaluating the Options**:
- Nematode: Correct, as filariasis is caused by nematodes (roundworms).
- Leech: Incorrect, as leeches belong to the phylum Annelida and do not cause filariasis.
- Bedbug: Incorrect, as bedbugs belong to the phylum Arthropoda and are not involved in filariasis transmission.
- Flea: Incorrect, as fleas also belong to the phylum Arthropoda and do not cause filariasis.

6. **Conclusion**: The correct answer to the question is that filariasis is due to infection by nematodes.

**Final Answer**: Filariasis is due to infection of nematodes.

---