Malaria Flashcards
what are the five species of plasmodium that cause malaria in humans?
- falciparum
- vivax
- malariae
- ovale
- knowlesi
what is the distribution of p. falciparum?
world wide
what is the distribution of p. vivax?
mostly in Asia, some in sub-Saharan Africa
what is the distribution of p. malariae?
world wide
what is the distribution of p. ovale?
Africa, parts of Asia, Pacific Islands
what is the distribution of p. knowlesi?
Malaysia, parts of Southeast Asia
most of the cases of malaria are caused by what species of plasmodium?
falciparum and vivax
which two species of plasmodium can take on a dormant form in the liver? what is the name of this form?
- vivax and ovale
2. hypnozoite
what is the clinical feature of malaria?
malarial paroxysm
malarial paroxysm is associated with which phase of the plasmodium life cycle?
synchronous release of merozoites and lysis of RBCs
what are the stages of malarial paroxysm? how long is each phase?
- cold - 15-60 minutes
- hot - 2-6 hours
- sweat - 8-12 hours
what is the duration and pattern of paroxysm for p. vivax and ovale?
every 48 hours (tertian)
what is the duration and pattern of paroxysm for p. malariae?
every 72 hours (quartan)
what is the duration and pattern of paroxysm for p. falciparum?
roughly every 48 hours
what is the duration and pattern of paroxysm for p. knowlesi?
every 24 hours
the most severe form of malaria is caused by what species? why?
- falciparum
2. highest parasitemia - more than 20% of circulating RBCs can become infected
what is the most common species of plasmodium?
falciparum
what is the most severe complication of of falciparum malaria?
cerebral malaria
what is the incubation period for falciparum?
1-2 weeks
what is the incubation period for vivax and ovale?
2-3 weeks
what is the most severe complication for vivax and ovale?
splenic rupture
what is the incubation period for malariae?
3-6 weeks
symptomatic recrudescence occurs in which species of plasmodium?
malariae
what are the three mechanisms of malarial anemia?
- RBC rupture
- suppression of erythropoiesis by cytokines
- RBC destructionby spleen
falciparum and knowlesi infect what type of RBC?
any type, old or young
vivax and ovale infect which type of RBC?
only reticulocytes
vivax - must have Duffy blood group determinants
ovale - Duffy negative or positive
malariae infects which type of RBC?
old RBCs
what are the secondary symptoms of malaria?
- hypoglycemia / lactic acidosis - CNS depression
2. microvascular sequestration - cerebral malaria
what are the hallmark features of falciparum on PBS?
- purple bananas!! (gametocytes)
2. multiple ring forms
what are the hallmark features of vivax and ovale on PBS?
- pale bloated RBCs
2. Schuffner dots
what are the hallmark features of p. malariae on PBS?
band forms
babesiosis is transmitted by what vector?
tick
which populations are most vulnerable to babesiosis infection?
elderly, asplenic, immunosuppressed
what is the hallmark sign of babesiosis on PBS?
maltese cross
what is the treatment for babesiosis?
quinine and clindamycin
most of the malaria drugs target what form of the parasite?
asexual blood forms
where is the only place where chloroquine can responsibly be prescribed for malaria?
west of the Panama Canal - Mexico, Haiti, Dominican Republic
what is the major adverse effect of quinine?
hypoglycemia - induces insulin secretion
what drug is used in areas that are resistant to chloroquine?
mefloquine
which drug kills the hypnozoite forms of plasmodium?
primaquine
what is the major toxicity for primaquine?
RBC lysis in persons with G6PD deficiency
radical cure is necessary for following clinical cure of what species of plasmodium?
vivax and ovale
