Flashcards in Parasitology: Protozoa Deck (19):
What are the 4 classes of protozoa?
1. Amoebae (pseudopodia)
2. Flagellates (flagella)
3. Ciliates (cilia)
4. Apicomplexans (gliding)
Describe the life cycle of Entamoeba histolytica:
protozoa, fecal-oral, DIRECT
What are the 5 means of damage to the host by protozoa? Give examples.
1. Mechanical (Giardia-barrier to fat absorption, Plasmodium)
2. Competition for host resources (Plasmodium- glucose)
3. Cytotoxicity (Entomoeba histolytica- releases liver enzymes that degrade liver)
4. Inflammation (Plasmodium- cytokines)
5. Inflammation (Leishmania- Th mediated damage)
What do Giardia do to harm the host?
prevent absorption of nutrients--> diarrhea
How does Entomoeba histolytica harm host?
Liver abscesses --> cytotoxicity to liver, chews through liver by releasing enzymes
What tests are done to confirm protozoa infection?
1. direct examination (Stool protozoa, Plasmodium)
2. Culture (Leishmania)
3. Antigen detection (Plasmodium-RDT, E. hystolitica)
4. Host antibody detection (E. histolytica, Trypnasomes)
5. Nucleic acid amplification (blood and tissue protozoa)
6. Radiologic (amoebic liver abscess)
What are the medical treatments for protozoa infection?
1. Antibiotics (giardia, plasmodium-doxycyclin)
2. Antifungals (Leishmania- azoles, flucanazol)
3. Conventional anti-parasitics (all protzoa)
4. Herbs/plant extracts (Plasmodium)
5. Elements (Leishmania)
What are the international treatments for protozoa infection?
Percutaneous drainage (entamoeba histolytica abscess)
What is the life cycle of Leishmania?
Protozoa, vector-borne, INDIRECT (sandfly)
What is the clinical correlate of Leishmania?
skin ulcer (really bad to face!)
Where are oligoparasitic protozoa found?
Where are polyparasitic protozoa found?
-Oligoparasitic: mucocutaneous, cutaneous (CMI inc)
-Polyparasitic: diffuse cutaneous, visceral (Ab inc)
What is the main cause of tissue injury in Leishmaniasis?
host-parasite interaction: IMMUNE mediated injury
What is the 1st line therapy for Leishmaniasis?
Antimony (Sb, element)
Toxic! (cardiotoxic, hepatotoxic, nephrotoxic, haemotoxic, toxic to pancreas)
What are the 4 main Rx for Leishmaniasis?
-ABs: Azithromycin, Paromomycin
-Antifungals: Flucanazole, Amphotericin
-Elements: Pentavalent Antimony
What is the life cycle of Malaria?
protozoa, vector-borne, INDIRECT
How does P. Falciparum (malaria) cause host damage?
Obstruction of capillaries
How is Malaria diagnosed?
-direct examination of blood film
-antigen detection: RDT= rapid diagnostic test
-nucleic acid amplification (PCR)
How is Malaria caused by Plasmodium treated?
-ABs: Doxycycline, Clindamycin
-Conventional Antiparasitics: Chloroquine, Mefloquine (erythrocyte cycle)
-Herbs/Plants: Artemisinin, Quinine