Microbiology Giardia lamblia: A Is the only flagellate parasite without a cystic stage B Infection happens by ingestion of trophozoites in food and water C Is the only protozoan parasite found in the lumen of small intestine D May sometimes invade the blood stream and cause ectopic lesions 💡 Explanation Giardia lamblia: ✓ Correct Answer: C. Is the only protozoan parasite found in the lumen of small intestine