Week 3: Extraintestinal Protozoa Flashcards
What is the malaria vector (give organism and genus)? What is the post-bite incubation time?
Anopheles mosquito
Incubation time post-bite: 8-24 days
What are the 4 main Plasmodium species for malaria?
- P. vivax
- P. falciparum
- P. malariae
- P. Ovale
List the Plasmodium species in order from the one that contributes the most to malarial infections to the one that contributes the least
- P. vivax (80%)
- P. falciparum (15%)
- P. malariae (4%)
- P. Ovale (1%)
Describe the malarial life cycle. Include infective and diagnostic stages
- Mosquito injects sporozoites into human bloodstream (infective)
- Liver gets infected and houses schizonts
- Schizonts rupture and release merozoites
- Merozoites infect RBCs
- Ring stage forms (trophozoite )in RBC (diagnostic)
- Trophs asexually multiply and multiply as merozoites (schizont stage) (also diagnostic)
- Schizonts rupture and release merozoites, thus rupturing RBCs (also diagnostic)
- Merozoites infect other RBCs as trophozoites. Cycle continues
- Some merozoites become gametocytes instead of trophozoites
Define the following:
Schizont
Schuffner’s dots
Merozoites
Gametocyte
Trophozoite
Schizont = multi-nucleated cell that contains merozoites. Rupture releases these daughter merozoites
Schuffner’s dots = Stippling in RBCs
Merozoites = free Plasmodium parasite that infects RBCs. Mature in to trophs or gametocytes
Gametocyte = Sexual precursor cell that mates and undergoes meiosis
Trophozoite = motile, reproductive, feeding stage of parasite. Ring-form for malaria
What are some natural mechanisms of malarial resistance? Does complete immunity exist?
Duffy Ag negative individuals resistant to P. vivax due to change in RBC surface antigens
Sickle cell anemia trait
Complete immunity does not exist
List some malaria symptoms
-Splenomegaly
-dry cough
-vomiting/nausea
-muscle/joint pain
-jaundice
-fever
-shivering
-fatigue
-convulsions
What are the stages of paroxysm?
- Cold (shivering)
- Hot (dry burning sensation of skin + headache)
- Sweating (declining temp, fatigue, weak)
How do you detect and identify malaria?
Thick smear = detection
Thin smear = identification (examine at least 300 fields at 100x)
Identify the following traits of this malarial parasite. Which Plasmodium species is this?
Plasmodium falciparum
*Note that acolé means edge ring
The following is the gametocyte for which malarial species?
Plasmodium falciparum
Identify this malarial parasite and stage (ring, schizont, gametocyte)
P. falciparum ring form
Identify this malarial parasite and stage (ring, schizont, gametocyte)
P. malariae ring form
Identify this malarial parasite and stage (ring, schizont, gametocyte)
P. malariae ring form
Identify this malarial parasite and stage (ring, schizont, gametocyte)
P. malariae schizont
Identify this malarial parasite and stage (ring, schizont, gametocyte)
P. malariae gametocyte
Identify the components in the image. Which ring-form malarial parasite is this?
P. vivax
Identify this malarial parasite and stage (ring, schizont, gametocyte)
P. vivax amoeboid troph