Question

Microfilariae circulate in the peripheral blood vessels during night. What could be a probable reason for this behaviour of the worms?

• A. The deep blood vessels do not provide a conducive environment during night
• B. It ensures the vector, the night time mosquito, will have a higher chance of transmitting them elsewhere
• C. Female adult parasite produces around 50,000 larvae per day. All of them cannot stay together.
• D. Blood flows faster in peripheral blood vessels enabling them to circulate freely

Answer 1

The correct option is B It ensures the vector, the night time mosquito, will have a higher chance of transmitting them elsewhere

Adults filarial worms reside in the lymph nodes where the female parasite reproduces to form larvae, while the larvae called microfilariae circulate in the bloodstream. During the day, the microfilariae move through the blood vessels deep inside the body, and during the night, they move to the superficial parts, which are the capillaries in the skin. The fact that the microfilariae are found in the peripheral blood during these hours, may ensure that the vector, the night time mosquito, will have a higher chance of transmitting them elsewhere.