Question

(I) Write the scientific names of the two species of filarial worms causing filariasis.
(II) How do they affect the body of infected persons ?
(III) How does the disease spread ?

Hint:

Always underline scientific names when writing them manually (Wuchereria bancrofti) to adhere to biological nomenclature standards.

Answer 1

Concept: Filariasis (commonly known as Elephantiasis) is a helminthic vector-borne disease that induces progressive structural changes within the human lymphatic architecture. Part (I): Scientific Names of Pathogens
The two parasitic nematode worms responsible for causing lymphatic filariasis are:
• Wuchereria bancrofti
• Wuchereria malayi Part (II): Effect on the Human Body

• The adult filarial worms reside in the lymphatic vessels, primarily targeting the lower limbs and genital organs.
• They trigger a chronic, slow-progressing inflammatory reaction over many years.
• This continuous inflammation causes severe blockage of lymphatic drainage, leading to intense fluid accumulation (oedema). As a result, the lower legs swell heavily to resemble those of an elephant, giving rise to the name elephantiasis.
• In males, the scrotum can also become severely deformed and enlarged. Part (III): Mode of Transmission

• The disease is transmitted to a healthy individual through the bite of an infected vector, specifically the female Culex mosquito.
• When the mosquito feeds on human blood, the infective third-stage filarial larvae escape from the insect's proboscis and enter the skin to reach the lymphatic circulation.