Immunity to schistosomes can become __ in spite of immune response.

• A. Chronic
• B. Acute
• C. Latent
• D. Resolved

Answer: (A)

Chronic infection is when a parasite remains in the body for a long time despite the immune system mounting a response. Schistosomes can persist for years in the host; adult worms survive and continue producing eggs even as the immune system reacts. This partial immunity may reduce worm fecundity and limit some pathology, but it doesn’t completely eradicate the parasites. The result is an ongoing, long-term infection with ongoing tissue reactions driven by the eggs, which is the hallmark of chronic disease.

Acute would imply a short, sudden onset; latent would suggest dormancy with no active disease; resolved would mean the infection has been cleared. None of those best describe a situation where the immune response coexists with a continuing Schistosoma infection.