malaria Flashcards
what does malaria infect ?
red blood cells are infected by plasmodium
how are you infected by malaria ?
bite of anopheles mosquito
caused by plasmodium species
what is the most dangerous form of malaria ?
falciparum
whata re the common symptoms of malaria ?
paroxysm of fever
anemia due to RBC infection may be associated with jaundice
splenomegaly
non specific symptoms
what are the rare symptoms of malaria ?
altered consciousness
seizures
blackwater fever
what is blackwater fever ?
rare symptom associated with the falcipatum species where there is renal failure along with hemoglobinuria
what is the presentation of P vivax and ovale ?
tertian fever type, where there is a fever every three days
why does recurring infection happen in the ovale and vivax species ?
becasue there is a dormant form in the liver
hypnozoites
what is the treatment for the dormant form of p vivax and ovale ?
primaquine
what is the presentation of p malariae ?
classically has a 72hr cycle of fevers
fever every 4 days
what type of RBC invasion is associated with p falciparum vs any other type of malaria ?
the falciparum invades RBCs at any age
whilst the rest only invade the mature form - reticulocytes
what are the virulence factors associated with falciprum ?
induces sticky knobs on RBC surfaces
these knobs are made up of parasite proteins (PfEMP1)
which results in occluded capillaries
what do the “ sticky knobs” on RBCs infected by falciparum cause ?
results in occluded capillaries in the brain ( cerebral malaria)
renal failure (blackwater fever)
how is a diagnosis of malaria made ?
geimsa stain peripheral blood smear
what forms of the parasite are seen on peripheral blood smear ?
trophozoite
schizont with merozoites
what are the features that make red blood cells more or less likely to be attacked by malaria ?
1- duffy antigen - which is necessary for vivax infection
an absence of it is protective
2- sickle cell - those with sickle cell are immune to malaria (HbS have a lower risk)
3- thalassemia reduces parasite multiplication
what is the mechanism of chloroquine ?
choloroquin blocks the parasite from making hemozoin , which is originally heme but was made so by the enzyme heme polymerase
which is blocked by chloroquine
( the heme portion is toxic to the plasmodium)
what is the main use of chloroquine ?
only kills the erythrocytic form
what is the main adverse effect associated with chloroquine ?
retinopathy associated with long term use
what drugs are used for severe infections of malaria ?
artesunate
quinidine
what drug is commonly used for prophylaxis of malaria ?
mefloquine
which drug is used in chloroquine resistant areas ?
mefloquine
what drug is used to treat the liver phase of malaria ?
primaquine
what are the other uses of malaria drugs ?
immune suppression , causes decreased activation of B cells
Ra and lupus
