Question

In India, filariasis is transmitted by.
A. Culex fatigans
B. Anopheles culicifacies
C. Musca domestica
D. Aedes aegypti

Answer 1

Hint: Filariasis is a disease caused by round, coiled thread-like parasites belonging to phylum Nematoda, superfamily- Filarioidea. It is a vector borne disease which requires a carrier organism for the transmission of the disease. It is transmitted by mosquitoes.
Complete step-by-step answer:
Filariasis is caused by the worm Wuchereria bancrofti or Brugia malayi. The host of these parasites are humans. It is one of the vector borne diseases.
The vectors for these worms are various mosquito species such as Culex sps., M.uniformis etc. The parasites come in contact with humans by penetrating the skin or through the hole created by the mosquito bite. When an infected mosquito bites a healthy person the larvae of the worms move inside the blood of the primary host (human) and travel to the lymphatic system and lymph nodes. They grow there and absorb nutrition from the host. The adult parasite grows and produces a large number of microfilariae which remain in the circulating blood. When a mosquito again, bites this infected person, it gets converted into a vector and now this vector can further spread the disease.
Culex, Aedes and Anopheles mosquito are vectors for Wuchereria bancrofti and Mansonia and Anopheles are vectors for Brugia malayi. In India, this disease is commonly spread by Culex fatigans, which is a medium-sized mosquito, seen in the tropical and subtropical regions of the world. It is also known as Culex quinquefasciatus.
Therefore, the correct answer is option A- Culex fatigans.
Note: -Anopheles culicifacies causes malaria in India.
-Musca domestica is the common housefly seen on food and various places where garbage is accumulated.
-Aedes aegypti causes yellow fever, chikungunya, zika fever, etc.