ConditionsDiseases List - back
ConDis
Cyclical infection of parasites that start at the liver and invade red blood cells and reinfects future mosquitos
Fundamentals:
Malaria Cycle - Life Cycle of Parasite
- Bite of infected mosquito (Anopheles sp.)
- Mosquito injects sporozoites
- Sporozoites invade the liver
- Hepatocyte/Parenchymal cells - Liver
- In the liver sporozoites transform into exoerythocytic parasites
- Schizogony - asexual reproduction
- Hepatocyte releases merozoites
- Further invading liver cells
- Exoerythrocytic parasites differeciate into gametocytes
- Another mosquito is infected by gametocytes
- Gametocytes transform into sporozoites
Stages of Infection
- Liver
- Blood - Erythrocytic
LOC:
Causes:
1)Genetic:
2)Pathogenic:
- Infection of parasites
- Plasmodium sp
- P. falciparum
- Only one patent erythrocytic cycle
- P. vivax - N. Korea - extreme temperate areas
- P. ovale
- P. berghei
- P. knowelsi - ? infectivity
3)Biochemical:
- G6P dehy deficiency "protects against falciparum malaria"
- Parasites require reduced glutathione and products of 5PP/PPP/3P for optimal growth
4)Anatomical:
Route Of Transmission ROT:
Pathogenesis:
1)Genetic:
2)Pathogenic:
- Parasite invades liver cells and red blood cells
- Parasite multiplies in cells
- Lysis releases more parasites to infect further cells
3)Biochemical:
4)Anatomical:
Specifics:
Invasion
Observations in Human Hepatoma cells (HepG2-A16) - innoculated by P. berghei
- Parasitophorous vacuole membrane - reacts with monoclonal antibody
- Plasma membrane of liver cell
- As sporozite enters there is a narrow band (rhoptries) a connection from sporozite to plasma membrane
- Sporozite is contained in the vacuole inside the cell
- 24 hr transformation into trophozoites
- Pellicle and subpellicular microtubules break down
Exoerythrocytic Stage
- Schizogony occurs bet 24-48 hrs
- Nuclear division forming many nuclei
- EE are larger and have mroe nuclei than liver cells
- 68 hr EE merozoites (infectious to mice)
Differenciation - Large Cells
- Less reactive to P. vivax monoclonal antibody
- 24 hr trophozoites transformation
- EE parasites grow slowly until day 3
- Day 5 nuclear division and schizonts rapidly grow until Day 9
- May have 80 micrometer and 1k nuclei
- Primary schizonts: small nondividing parasites evident after schizogony
- Resemble hypnozoites - connected with liver infection relapses of malaria
Differenciation - Small Cells
- Reactive to P. vivax monoclonal antibody
- Small EE seen at Day 5
- Grow until Day 9
- Differenciation seems equal numbers of small and large cells
- Sporozites are immunogenic
- Elicit antibody response in humans = protection? Nussenzweig Immunization against sporozites
- Species specific cirumsporozite protein antigens: covers mice/primate/human malarial sporozites
- Interaction to the monoclonal antibodies a ruins/reduces the infectivity into hosts
- P. knowelsi - CS protien = 12 AA repeated 12 times
- P. falciparum - CS protien = 41 tandem repeats of tetrapeptide
Symptoms:
Diagnosis:
Treatment:
Prevention:
Additional Information:
- Malaria and the Liver - Hollindale. 1985
