Malaria plasmodium Flashcards
host
humans, not zoonotic
vector
anopheles mosquito, needs water to breed
morphology
Falciparum - numerous fine rings, double chromatin dots, RBC not enlarged, marginal forms
Vivax - thick signet ring, enlarged RBC
Ovale - oval RBC, enlarged
Malariae - band shaped, RBC not enlarged
transmission
Female anopheles bites human, infects host w/ sporozoites in salivary gland
Mosquito attracted to pregnant women
lifecycle?
mosquito ingests blood meal w/ gametocytes –> reproduce in gut for 5 days, –> oocysts w/ sporozoites –> sporozoites migrate to liver –> after 8 days mature liver schizont releases merozoites –> infect RBC’s (trophozoite)–> release gametocytes after 3 days
hypnozoites dormant in liver -vivax and ovale
stable vs. unstable
Stable - transmission throughout year, acquired immunity, highest rate mortality in youth, anemia, pattern repeats annually
Unstable - transmission seasonal, less intense, cerebral malaria, low immunity, epidemics
sickle cell anemia heterozygote, thalassemia, g6pd def.
infected RBC sequestered to ER system –> low O2 = k loss, low pH inhibits growth, faster clearance by spleen
diagnosis
thick and thin blood smear
symptoms
cold stage –> hot stage (fever) –> sweating stage (temp falls)
malariae - every 4th day, vivax/ovale - every 3rd day, falciparum - drop in fever every 3rd day
Hemolysis of RBC’s (anemia), hepatosplenomegaly, microcirculatory arrest (RBC’s clump), renal failure, jaundice, pulmonary edema, nausea and vomiting, delirium, stupor, coma, disorientation, convulsions
cerebral malaria
schizonts adhered to endoth in brain
coma, convulsions, abnormal posturing, retinal hemorrhages, dysconjugate gaze
treatment
for blood - artemeter/lumafantrine (falciparum), quinine or quinidine (all), chloroquine (vivax, ovale, malariae)
for liver - primaquine (vivax, ovale)
for prohylaxis - mefloquine, doxycycline, chloroquine, atavoquone and proguanil
control
prophylaxis, insecticide treated nets
