Protozoa and helminths

• What are protozoa?

  Tiny, single-celled organisms
• How do protozoa relate to diseases?

  They can cause diseases in humans
• How do helminths differ from protozoa in size?

  Helminths are much larger than protozoa
• Where can roundworms mature in the body?

  In the intestine or remain immature in skin/organs
• What are the key differences between Cestodes (tapeworms) and Trematodes (flukes)?

  Cestodes reside in the intestine, while Trematodes reside in the liver
• What are the two main groups of helminths?

  Flatworms and roundworms
• What are helminths classified as?

  Multicellular parasites
• Why does the sporulation of the oocyst require several days and oxygen?

  Sporulation occurs outside the host
• What is the name of the non-infectious stage of the oocyst?

  Unsporulated oocyst
• Where do flatworms typically live in the body?

  In the intestine and liver or blood
• What is the name of the life cycle shown in the image?

  Eimeria Life Cycle
• What are the two main reproductive stages in the Eimeria life cycle?

  • Sexual gametogony
  • Asexual schizogony
• What types of flatworms are mentioned?

  Tapeworms and flukes
• What happens during the asexual schizogony stage?

  • Merazoites released from schizont
  • Schizogony (asexual reproduction)
  • Schizont
• Where does the oocyst enter the host when swallowed?

  Oocyst enters gut when swallowed
• What is the name of the infectious stage of the oocyst?

  • Sporulated oocyst (infectious)
• What are helminths?

  Multicellular parasitic worms
• What is the life cycle pattern of Eimeria?

  Alternating host and environment phases
• What is the significance of cysts in parasites?

  Cysts survive in the environment
• What are the key differences between pathogenic and nonpathogenic protozoa shown in the image?

  • Pathogenic protozoa can cause disease in humans, while nonpathogenic protozoa do not.
  • Pathogenic protozoa include Giardia, Cryptosporidium, Cyclospora, and Isospora, while nonpathogenic protozoa include Entamoeba coli, Endolimax nana, and Iodamoeba.
• What is the process called when oocysts become infectious in the environment?

  Sporogony
• What are the key differences between the various intestinal helminths (worms) shown in the image?

  • They have different morphologies, life cycles, and modes of transmission.
  • Some, like Ascaris and Trichuris, are roundworms, while others like Taenia and Diphyllobothrium are tapeworms.
  • They can be contracted through ingestion of contaminated food/water, skin penetration, or consumption of undercooked meat/fish.
• What occurs when Eimeria is ingested?

  Syngamy and schizogony cycles occur in the gut
• What are the different types of intestinal helminths (worms) affecting travelers shown in the image?

  • Ascaris (roundworm)
  • Hookworm
  • Trichuris (whipworm)
  • Strongyloides
  • Taenia (tapeworm)
  • Hymenolepis
  • Diphyllobothrium (fish tapeworm)
• How do the symptoms of diseases caused by protozoa and helminths vary?

  • Symptoms depend on the parasite's location
  • Severity of infection influences symptoms
• What is the fecal-oral route of transmission for protozoa?

  • Ingesting contaminated water or food
  • Example: Giardia spreads through unclean water
• What is the key difference between protozoa and helminths?

  • Protozoa are single-celled organisms
  • Helminths are multicellular organisms
• What are the different types of intestinal protozoa and helminths affecting travelers shown in the image?

  • Pathogenic protozoa: Giardia, Cryptosporidium, Cyclospora, Isospora
  • Nonpathogenic protozoa: Entamoeba coli, Endolimax nana, Iodamoeba
  • Intestinal helminths: Ascaris, Hookworm, Trichuris, Strongyloides, Taenia, Hymenolepis, Diphyllobothrium
• What are the different types of Nematodes (roundworms)?

  • Mature in humans
  • Fail to mature in humans
• What are the life cycle forms of parasites mentioned?

  • Active feeding stages (tropozoites)
  • Resistant forms (cysts)
• How can certain parasites be transmitted sexually?

  • Direct transfer during sexual activity
  • Some parasites infect through sexual contact
• How does the life cycle of Eimeria differ from the life cycle of Plasmodium (the malaria parasite)?

  Eimeria has a direct life cycle, while Plasmodium has a more complex life cycle involving a mosquito vector
• What are the key differences between Nematodes that mature in humans and those that fail to mature in humans?

  • Nematodes that mature in humans reside in the intestine
  • Nematodes that fail to mature in humans reside in the cutaneous and viscera tissues
• Can helminths be visible to the eye?

  Yes, they are often visible to the eye
• What are the characteristics of flatworms and roundworms?

  • Flatworms (platyhelminths):
  • Include tapeworms and flukes
  • Live in intestine, liver, or blood
  • Roundworms (nematodes):
  • Can mature in intestine
  • May remain immature in skin/organs
• What is the difference between Platyhelminthes (flatworms) and Nematodes (roundworms)?

  Platyhelminthes are flatworms, while Nematodes are roundworms
• What happens to unsporulated oocysts in Eimeria's life cycle?

  They pass in feces and undergo sporogony
• What is the causative agent of Tapeworm infections?

  Taenia species
• If a host ingests a sporulated oocyst, what happens next in the life cycle?

  Sporozoites invade gut cells
• What are the symptoms of Tapeworm infections?

  Weight loss and digestive discomfort