Question

Filariasis is caused by.

• A. Dead adult filariae
• B. Presence of bacteria in filarial wall
• C. Microfilariae
• D. Biting of filarial worm

Answer 1

Answer: (C)

Microfilariae

Lymphatic filariasis is caused by infection with parasites classified as nematodes (roundworms) of the family Filariodidea Infection occurs when filarial parasites are transmitted to humans through mosquitoes. Adult worms nest in the lymphatic vessels and disrupt the normal function of the lymphatic system. The worms can live for approximately 6–8 years and, during their lifetime, produce millions of microfilariae (immature larvae) that circulate in the blood. Mosquitoes are infected with microfilariae by ingesting blood when biting an infected host. Microfilariae mature into infective larvae within the mosquito. When infected mosquitoes bite people, mature parasite larvae are deposited on the skin from where they can enter the body. The larvae then migrate to the lymphatic vessels where they develop into adult worms, thus continuing a cycle of transmission.

So, the correct answer is 'Microfilariae'.