Parasitology

By completing this question set, you will trace parasite lifecycles from acquisition to disease, explaining why each organism produces its characteristic clinical syndrome. You will apply the IgA deficiency predisposition to explain chronic Giardia, the erythrophagocytosis criterion to identify E. histolytica, and the acid-fast stain and chlorination resistance of Cryptosporidium to distinguish it from other waterborne pathogens. For Toxoplasma, you will trace the bradyzoite-to-tachyzoite reactivation in AIDS to explain ring-enhancing brain lesions and distinguish congenital toxoplasmosis (diffuse calcifications + hydrocephalus) from congenital CMV (periventricular calcifications). For malaria, you will trace sporozoites through liver hepatocytes to RBCs and explain how each Plasmodium species' RBC biology produces its characteristic fever periodicity and thin smear findings. You will explain why P. falciparum knobs cause cerebral malaria while P. vivax/ovale hypnozoites cause relapsing disease. For Trypanosoma cruzi, you will trace amastigote intracellular destruction of cardiac and enteric autonomic neurons to explain dilated cardiomyopathy and megaesophagus decades after initial infection. For helminths, you will explain eosinophilia as the immune response to tissue-invasive larvae and apply this principle to identify Löffler syndrome, Trichinella myositis, and hyperinfection syndrome.