Apr27 M2-Malaria Flashcards
returned traveller with fever: first thing on ddx
malaria
malaria is what type of pathogen
systemic protozoa (parasite)
organisms that cause malaria
the plasmodium species
vector of malaria
anopheles (genus) mosquito
malaria zoonosis
none for 4 of the 5 species. (knowlesi has monkey reservoir)
for 4 of 5 species, human reservoir only and no zoonosis
5 species of malaria
- falciparum (high parasitemia and mortality)
- vivax
- ovale
- malariae (benign)
- knowlesi (high parasitemia and mortality + only with zoonosis)
1st step of malaria life cycle
anopheles bites you and sporozoides enter you. sporozoides in your blood seen in your liver
2nd step of malaria life cycle (after sporozoides reach liver)
development phase of sporozoides in the liver. takes a couple weeks. then shizonts escape from the liver
3rd step of malaria life cycle (after escape from liver)
erythrocytic phase (shizonts infect RBCs). erythrocytic cycle repeats: malaria goes in RBC, multiplies, RBC bursts, goes out to infect other RBCs and amplify
4th step of malaria life cycle (after erythrocytic phase)
small % transforms in gametocytes. next mosquito that bites you eats a male and female gametocyte from your blood
5th step of malaria life cycle (after mosquito eats gametocytes from your blood)
malaria becomes infectious in the mosquito after a short time
how malaria is diagnosed
thick smear microscopy (know that it can look like many things, shizonts, young trophozoites = ring cells, etc.): see it in blood smear inside RBCs
(thin smear is to speciate)
worst malaria species and why
plasmodium falciparum. worst symptoms. multiplies in high degree and causes lot of damage to RBCs.
malaria symptoms and signs
- chills, rigors, FEVER, perspiration, fatigue (constitutional symptoms), headache, delirium, confusion, coma, sob, jaundice
- anemia, splenomegaly
how fever helps for malaria dx
- most malaria synchronizes its RBC bursting
- tertian fever (1 day on 1 day off) = vivax or ovale, sometimes with falciparum
- quartan fever (1 day on 2 days off) = malariae
time interval between the mosquito bite and the fever in malaria
2 weeks
malaria clinical presentation that is not to be missed
fever mixed with something else making you think of another system (+cough or +abd pain or +diarrhea or +headache or +vomiting). can still be malaria
avg interval between fever and death in malaria infection
7-8 days
causes of death in malaria
- cerebral malaria
- ARDS
- renail failure
- hematological
- shock
- sepsis
- ruptured spleen
black water fever (syndrome seen in malaria) charact
- massive hemolysis
- bilirubin in urine so BLACK urine
celebral malaria in WHAT SPECIES, symptoms of cerebral malaria and its patho cause
- cause = endothelial damage and cytokin dysregulation. ischemia less important
- coma
- in falciparum*
ARDS in malaria cause and symptoms
- endothelial dysfunction and fluid leak in airspace
- sob
what can protect you from malaria
- being in an area of moderate or high transmission gives you moderate or high PARTIAL immunity
- polymorphisms (Hb, RBCs, etc.)
microscopy modality to diagnose malaria and modality to speciate the malaria
thick smear to diagnose***
thin smear to speciate
malaria treatment+prophylaxis in malaria sensitive vs malaria resistant areas
- CHLOROQUINE for tx and prophylaxis in malaria sensitive areas
- QUININE for tx and mefloquine for prophylaxis in malaria resistant areas
3 ways drugs of malaria prophylaxis work
- kill parasites in the liver = CAUSAL PROPHYLAXIS
- kill asexual parasites in RBCs = SUPPRESSIVE PROPHYLAXIS
- kill sexual parasites (gametocytes) in RBCs = GAMETOCYTOCIDAL PROPHYLAXIS
goal of gametocytocidal prophylaxis
avoid transmission
causal prophylaxis how long you have to take it
1 week after your return
suppressive prophylaxis how long you have to take it
4 weeks after you return (because may take up to four weeks for the organism to get out of your liver)
what is defined as severe malaria
10% + parasitemia OR 5% + parasitemia with big problems (dehydration, renal failure, pulmonary edema, shock, etc.)
one controversial tx of malaria
exchange transfusion: take out one unit of blood, put it in phoresis machine, take out infected RBCs and put new ones in
how do you prevent malaria in chloroquine sensitive regions (central America)
- chloroquine 250mg x2 weekly
2. daraprim (pyrimethamine) 25 mg weekly
how do you prevent malaria in chloroquine resistant regions
- medications (mefloquine, atovoquone, chloroquine, doxycycline)
- PERMETHRIN treated bednet (bc anopheles = night biters)
how to avoid mosquitos (and prevent malaria)
- evening and night behaviors
- mosquito nets
- air conditioning
- screens
- mosquito repellants (+ put on wall bc land there after they eat)
- pyrethrum coils
how to kill anopheles
- destroy breeding site
- fog spraying
- residual spraying
how to kill plasmodium
chemoprophylaxis (chloroquine)
