Malaria: Protozoa II Flashcards
1
Q
Malaria is caused by 4 Plasodium
A
- P. Malariae
- P. Ovale
- P. Vivax
- P. Falciparum
2
Q
Malaria life cycle in 2 organisms
A
- mosquito (sexual cycle)
2. Human (asexual cycle)
3
Q
Malaria life cycle
A
- Infected mosquito bites human; sporozoites migrate through bloodstream to liver of human
- sporozoites undergo schizogony in liver cells; merozoites are produced
- Merezoites released into bloodstream from liver infects new RBC
- Merezoite develops rings stage in RBC
- Ring stage grows and divides producing mereozoites
- Merozoites are released when RBC ruptures; some merozoites infect new RBC, some develop into male and female gametocytes
- Another mosquito bites infected human and ingests gametocytes
- In mosquito digestive tract, gametocytes unite to form zygot
- Resulting sporozoites migrate to salivary glands of mosquito
4
Q
Malaria: Exoerythrocytic Schizogony
A
- hepatocyte invasion
- asexual replication
- no overt pathology
5
Q
relapse
A
hypnozoite
6
Q
recrudenscence
A
subpatent
7
Q
Erythrocytic stage
A
- intracellular parasite undergoes trophic phase
- young trophozoite called ‘ring form’
- ingest host haemoglobine
8
Q
Erythrocytic Schizogony
A
- nuclear division
- erythrocyte ruptures releasing merozoites
- blood stage results in disease symptoms
9
Q
Malaria clinical features is characterised by
A
acute febrile attacks (malaria paroxysms)
10
Q
Manifestations and severity depends on
A
species and host status: immunity, health, nutritional state, genetics
11
Q
recrudescences and relapses can occure over
A
months or years
12
Q
Paroxysms associated with
A
synchrony of merozoite release
13
Q
Falciparum is different
A
may not exhibit classic paroxysms and thus has continous fever
14
Q
Gametogenesis occurs in
A
mosquito gut.
- Exflagellation most obvious
- gametocyte activating factor in mosquito
15
Q
Sporogony
A
occurs in mosquito
- fusion of micro and macrogrametes
- zygote–>ookinete
- ookinete transverses gut epithelium
