Malaria Flashcards
What kind of infection is malaria?
blood infection
malaria person-to-person?
Nope
2 main type os malaria?
P. Falciparum
P. vivax
Malaria affects who the most?
young children
pregnant women
insecticides effective in malaria?
resistance is increasing
majority of malaria caused by which plasmodium?
P. falciparum
Which plasmodium can be dormant in liver stage?
P. vivax
what’s special about P. knowlesi?
can be zoonotic infection and severe
Malaria normally cross-species? exception?
Not usually. except P. knowlesi
female or male mosquitos transmit?
female
immune response against what stage of infection?
blood stages
severe malaria affects?
- cerebral: coma, convulsions
- Anaemia: Respiratory distress/metabolic acidosis
- hypoglycaemia, kidney failure, clotting
how to treat mild malaria?
anti-malarial short course:
Aremisinin combo therapy (ACT)
How to treat severe malaria?
Intravenous anti-malarials 7-10 days
Aretemisinin/quinine
3 big things that happen in blood of malaria infection to cause severe illness?
- parasites
- inflammatory responses
- RBC destruction
3 kinds of malarial immunity
- prevent severe malaria
- prevent any malaria
- prevent malaria in pregnancy
main parasite factors that influence slow immunity development?
antigenic diversity
antigenic variation
5000 genes
main host factors that influence slow immunity development?
- inadequate response (children)
- in-functional response
- no immunity memory
what does it mean that plasmodium has +++ antigenic variation?
chronic and recurrent infections
3 genetic malarial resistance factors?
- sickle cell trait
- alpha thalassemia
- blood groups
Immune response to: Sporozoites: Infected hepatocytes Merozoites: Infected RBCs:
Sporozoites: Ab + T-cells
Infected hepatocytes: T-cells (CD8+)
Merozoites: Ab
Infected RBCs:Ab + T-cells
antibodies effective in liver stage?
nope
Why is immunity to liver stage limited?
low parasite load
short infection duration
4 cell-mediated responses involved in blood stage malarial protection:
- RBCs have no MHC
- CD4+ T-cells
- splenic clearance
- IFN-y
too much what in severe malaria?
TNF-a and pro inflammatory cytokine
antibodies to merozoites work how?
inhibit RBC invasion
how does antibodies to RBCs work?
opsonize for phagocytosis as parasite antigens expressed on RBC surface
how do you get a wrong immune response in malaria?
antibodies to liver stage of P. falciparum
2 approaches for malaria vaccine:
- Abs to sporozoites
2. Abs to mrozoites
RTS,S vaccine works how?
sporozoite segment coupled with virus-like particple with Hep B surface antigen and adjuvants.
How long does RTS,S vaccine last?
2 years
future of malaria vaccine focus on?
merozoite antigens
any vaccines for P. vivax?
Nope. only P falciparum
what does vaccines do for developing country economy?
Boosts it