Hunter: Schistosomiasis/Malaria

Question 1

What are the 3 major schistosomes?

Answer 1

Schistosoma mansoni
S. japonicum
S. haematobium

Question 2

What are the 2 minor schistosomes?

Answer 2

Schistosoma mekongi

S. intercalatum

Question 3

What is the infectious form in humans for schistosomes? Through what route do they invade the human? What is the reservoir?

Answer 3

cercariae; penetrate the skin; snail is the reservoir

Question 4

Cercarial penetration of skin can cause a transient (blank)
Migration of schistosomules through lungs can cause a (blank) that can be severe in heavy infections
Adult worms in superior mesenteric veins (mansoni and japonicum) and vesicle plexus of bladder (hematobium) cause (blank)

Answer 4

dermatitis; pneumonitis; no clinical symptoms

Question 5

Onset of egg production causes (blank) (allergic response);

Intestinal or urinary bladder symptoms are due to (blank) passing through tissue to lumen; cause severe hemorrhagic cystitis and gastroenteritis

Eggs swept up portal circulation to liver cause (blank); T cell-mediated delayed hypersensitivity reaction to the eggs

Blockage of sinusoids leads to pipestem fibrosis and (blank)

Answer 5

Katayama fever; eggs; granulomas; portal HTN

Question 6

3 clinical lab findings in schistosomiasis?

Answer 6

hepatosplenomegaly
eosinophilia
hyperimmunoglobulinemia

Question 7

List the three symptoms of disease caused by schistosomes

Answer 7

liver and spleen granulomas
fibrosis
inflammation

**all due to eggs trapped in tissues

Question 8

What drug do you use to treat schistosomes?

Answer 8

praziquantel

Question 9

This schistosome causes inflammation and fibrosis of the bladder and ureters; obstruction of the ureters leads to hydronephrosis and eventually to uremia

Answer 9

Schistosoma hematobium

Question 10

These two schistosomes are more likely to infect the gut than the urinary bladder

Answer 10

S. mansoni and japonicum

Question 11

Compare the structures of S. hematobium, japonicum, and mansoni eggs

Answer 11

S. hematobium: egg comes to a point on one end
S. japonicum: more rounded egg with a tiny bleb hanging off
S. mansoni: spiky bleb coming off of egg

Question 12

In the life cycle of plasmodium spp, the infectious form delivered from the bite of a mosquito is the (blank). This enters the bloodstream where it is now called a (blank). If it is in the latent stage, it is called (blank). When it infects the liver it is a (blank). When liver cells rupture, they release (blank); when the mosquito takes a meal, it ingests (blank)

Answer 12

sporozoite; merozoite; hynozoite; trophozoite –> schizont; merozoites; gametocytes

Question 13

When the parasite is undergoing its asexual life cycle in the LIVER from a trophozoite to a schizont, are there any symptoms? When the parasite is undergoing its asexual life cycle in the BLOOD, are there symptoms?

Answer 13

no, no clinical disease during liver stage; yes clinical disease when parasite is in blood

Question 14

What is the main cytokine responsible for the systemic inflammatory disease that is malaria?

Answer 14

TNF-alpha

Question 15

What causes the classic fever in malaria?

Answer 15

rupture of RBCs

Question 16

How often do the fevers occur in the following:

P. falciparum
P. vivax
P. ovale
P. malariea

Answer 16

P. falciparum: daily (malignant tertian)
P. vivax: every other day (benign tertian)
P. ovale: every other day (ovale tertian)
P. malariae: every third day (quartan)

Question 17

3 important clinical findings in malaria?

Answer 17

anemia
hepatosplenomegaly
hyperimmunoglobulinemia

Question 18

Which forms of malaria RELAPSE (liver hynozoites re-establish infection)?

Which forms of malaria do not relapse, but RECRUDESCE (subclinical infection becomes clinical disease)?

Answer 18

vivax and ovale relapse;

falciparum and malariae recrudesce

Question 19

The most common cause of sepsis and septic shock in the world

Answer 19

plasmodium falciparum

Question 20

What are these?

cerebral coma (schizonts sequestered in brain)
anemia
pulmonary edema
renal failure
shock
lactic acidosis
hypoglycemia
tropical splenomegaly
maternal death/stillbirth/low birth weight

glomerulonephritis

splenic rupture

Answer 20

complications of P. falciparum

complications of P. malariae

complications of P. vivax

Question 21

What do malarial parasites do to the shape of the RBC?

Answer 21

they alter the morphology, create knobs

Question 22

How can you diagnose malaria?

Answer 22

thick and thin blood films

Question 23

T/F: Mixed infection with P. falciparum and P. vivax can occur

Answer 23

true

Question 24

Which form of malaria has multiple ring stages and appliqué forms

Answer 24

P. falciparum

Question 25

Which form of malaria has enlarged erythrocytes with stippling

Answer 25

Plasmodium vivax

Question 26

Which RBC antigen can determine your susceptibility to vivax malaria?

Answer 26

Duffy blood group

**duffy + (FyA)

Question 27

Heterozygotes with this condition have increased survival in malaria

Answer 27

sickle cell trait: HbA/HbS

Question 28

This allele is protective against malaria in West Africa

Answer 28

HLA-B53

Question 29

This drug kills erythrocytic forms of malaria

Answer 29

chloroquine

Question 30

This drug kills hepatic forms of malaria (liver hypnozoites) and prevents relapses with vivax and ovale

Answer 30

primaquine

Question 31

T/F: Drug resistance in malaria is widespread; particularly chloroquine resistance

Answer 31

True

Question 32

What is used for travelers to prevent malaria?

Answer 32

chemoprophylaxis

Question 33

Why has malaria not been eradicated?

Answer 33

drug resistant forms of the parasite
mosquito resistance to DDT
Wars and massive population movements
Difficulties in obtaining sustained funding from donor countries
Lack of community participation in host countries