lecture 14, protozoa plasmodium part 2 Flashcards
significance of red blood cells against malaria
adapted to reduce Plasmodium infection
how have people living in endemic areas for malaria, acquired immunity?
they have low levels of parasite in their blood but do not acquire the disease
how is acquired immunity kept up?
continual pressure by the parasite is needed, otherwise acquired immunity does not last
what do we know about acquired immunity?
- slow to develop
- short lived
- non-sterilizing
what we dont know about acquired immunity?
the factors involved with this process
what are the limitations to fully eradicating malaria?
- world wide drug resistance
- limited acquired immunity requires repeat infections
- no vaccine available with operational impact
why is it important to understand host-parasite interactions?
- only a limited number of anti-parasitic compounds commercially available
- development of new drugs is very slow
- no guarantee of fully protective vaccines for all in the near future
what are the major clinical features of malaria?
- acute febrile attacks
- splenomegaly
- coma
how does malaria affect red blood cells?
destroys them, by replicating inside of them and then bursting the erythrocyte to leave
what is the host reaction of the bursting of red blood cells?
fever, shivering, convulsions, vomiting, and anemia - caused by hemolysis
what is the classical symptom of malaria?
cyclical occurence of sudden coldness followed by stiffness and then fever and sweating lasting four to six hours
what is the significance of knobs?
- responsible for adhesion, found on the surface of infected red blood cell. knobs cause infected RBCs to adhere to the endothelium and to each other.
- the ability to adhere makes the parasite lethal
- only found on plasmodium falciparum
why is adhesion important to the parasite?
avoids splenic clearance
adhesion leads to symptoms found in …
cerebral and maternal malaria
what is maternal malaria?
parasites adhere to the lining of the placenta- but they DO NOT cross the placenta to infect the fetus