The chronic nature of parasitic infections is caused by the host's

• A. Inability To Eliminate The Infective Agent.
• B. Tendency To Form Circulating Immune Complexes.
• C. Ability To Form A Granuloma Around The Parasite.
• D. Type I Hypersensitivity Response To The Infection.

Answer: (A)

Chronic parasitic infections persist because the host cannot completely eradicate the parasite. Parasites have strategies to avoid sterilizing immunity—hiding in protective niches, altering antigen presentation, delaying or dampening immune responses, or reproducing in a slow, persistent manner. This keeps their numbers in check but not eliminated, so the infection lasts a long time and can cause ongoing symptoms or intermittent flares.

Circulating immune complexes can form during ongoing infection and contribute to pathology, but they don’t explain why the infection remains in the first place. Granuloma formation is a containment effort by the immune system and, while it can accompany chronic infections, it’s not the fundamental reason for persistence. Type I hypersensitivity involves IgE-mediated allergic reactions and is not the mechanism behind the chronicity of parasitic infections.