Apr27 M2-Malaria

Question 1

returned traveller with fever: first thing on ddx

Answer 1

malaria

Question 2

malaria is what type of pathogen

Answer 2

systemic protozoa (parasite)

Question 3

organisms that cause malaria

Answer 3

the plasmodium species

Question 4

vector of malaria

Answer 4

anopheles (genus) mosquito

Question 5

malaria zoonosis

Answer 5

none for 4 of the 5 species. (knowlesi has monkey reservoir)

for 4 of 5 species, human reservoir only and no zoonosis

Question 6

5 species of malaria

Answer 6

• falciparum (high parasitemia and mortality)
• vivax
• ovale
• malariae (benign)
• knowlesi (high parasitemia and mortality + only with zoonosis)

Question 7

1st step of malaria life cycle

Answer 7

anopheles bites you and sporozoides enter you. sporozoides in your blood seen in your liver

Question 8

2nd step of malaria life cycle (after sporozoides reach liver)

Answer 8

development phase of sporozoides in the liver. takes a couple weeks. then shizonts escape from the liver

Question 9

3rd step of malaria life cycle (after escape from liver)

Answer 9

erythrocytic phase (shizonts infect RBCs). erythrocytic cycle repeats: malaria goes in RBC, multiplies, RBC bursts, goes out to infect other RBCs and amplify

Question 10

4th step of malaria life cycle (after erythrocytic phase)

Answer 10

small % transforms in gametocytes. next mosquito that bites you eats a male and female gametocyte from your blood

Question 11

5th step of malaria life cycle (after mosquito eats gametocytes from your blood)

Answer 11

malaria becomes infectious in the mosquito after a short time

Question 12

how malaria is diagnosed

Answer 12

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)

Question 13

worst malaria species and why

Answer 13

plasmodium falciparum. worst symptoms. multiplies in high degree and causes lot of damage to RBCs.

Question 14

malaria symptoms and signs

Answer 14

• chills, rigors, FEVER, perspiration, fatigue (constitutional symptoms), headache, delirium, confusion, coma, sob, jaundice
• anemia, splenomegaly

Question 15

how fever helps for malaria dx

Answer 15

• 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

Question 16

time interval between the mosquito bite and the fever in malaria

Answer 16

2 weeks

Question 17

malaria clinical presentation that is not to be missed

Answer 17

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

Question 18

avg interval between fever and death in malaria infection

Answer 18

7-8 days

Question 19

causes of death in malaria

Answer 19

• cerebral malaria
• ARDS
• renail failure
• hematological
• shock
• sepsis
• ruptured spleen

Question 20

black water fever (syndrome seen in malaria) charact

Answer 20

• massive hemolysis

- bilirubin in urine so BLACK urine

Question 21

celebral malaria in WHAT SPECIES, symptoms of cerebral malaria and its patho cause

Answer 21

• cause = endothelial damage and cytokin dysregulation. ischemia less important
• coma
• in falciparum*

Question 22

ARDS in malaria cause and symptoms

Answer 22

• endothelial dysfunction and fluid leak in airspace

- sob

Question 23

what can protect you from malaria

Answer 23

• being in an area of moderate or high transmission gives you moderate or high PARTIAL immunity
• polymorphisms (Hb, RBCs, etc.)

Question 24

microscopy modality to diagnose malaria and modality to speciate the malaria

Answer 24

thick smear to diagnose***

thin smear to speciate

Question 25

malaria treatment+prophylaxis in malaria sensitive vs malaria resistant areas

Answer 25

- CHLOROQUINE for tx and prophylaxis in malaria sensitive areas - QUININE for tx and mefloquine for prophylaxis in malaria resistant areas

Question 26

3 ways drugs of malaria prophylaxis work

Answer 26

- kill parasites in the liver = CAUSAL PROPHYLAXIS - kill asexual parasites in RBCs = SUPPRESSIVE PROPHYLAXIS - kill sexual parasites (gametocytes) in RBCs = GAMETOCYTOCIDAL PROPHYLAXIS

Question 27

goal of gametocytocidal prophylaxis

Answer 27

avoid transmission

Question 28

causal prophylaxis how long you have to take it

Answer 28

1 week after your return

Question 29

suppressive prophylaxis how long you have to take it

Answer 29

4 weeks after you return (because may take up to four weeks for the organism to get out of your liver)

Question 30

what is defined as severe malaria

Answer 30

10% + parasitemia OR 5% + parasitemia with big problems (dehydration, renal failure, pulmonary edema, shock, etc.)

Question 31

one controversial tx of malaria

Answer 31

exchange transfusion: take out one unit of blood, put it in phoresis machine, take out infected RBCs and put new ones in

Question 32

how do you prevent malaria in chloroquine sensitive regions (central America)

Answer 32

1. chloroquine 250mg x2 weekly | 2. daraprim (pyrimethamine) 25 mg weekly

Question 33

how do you prevent malaria in chloroquine resistant regions

Answer 33

1. medications (mefloquine, atovoquone, chloroquine, doxycycline) 2. PERMETHRIN treated bednet (bc anopheles = night biters)

Question 34

how to avoid mosquitos (and prevent malaria)

Answer 34

- evening and night behaviors - mosquito nets - air conditioning - screens - mosquito repellants (+ put on wall bc land there after they eat) - pyrethrum coils

Question 35

how to kill anopheles

Answer 35

- destroy breeding site - fog spraying - residual spraying

Question 36

how to kill plasmodium

Answer 36

chemoprophylaxis (chloroquine)