Protozoa

Question 1

Describe the life cycle of malaria?

Answer 1

Mosquito injects sporozoite into skin
Sporozoites go to the liver
Exoerythrocytic cycle: sporozoites–>early schizont–>late schizont–>merozoites rupture the hepatocyte and go into the bloodstream and attach to RBCs.
Erythrocytic cycle: Trophozoite (looks like engagement ring)–>early schizont–>late schizont–>merozoites that rupture.
Get gametocytes that go back into mosquito

Question 2

Which conditions can be treated with metronidazole?

Answer 2

GET GAP on the Metro
giardia
entamoeba
trichomonas
gardnerella
anaerobic bacteria
H. Pylori

Question 3

How do you treat malaria?

Answer 3

chloroquine (heme polymerase inhibitor)
latent phase–primaquine
resistant malaria: quinine + doxycycline

Question 4

What is the most common protozoal diarrhea?

Answer 4

giardia

Question 5

What are the important things to know about giardia?

Answer 5

campers drink water w/ giardia
causes fatty diarrhea, flatulence, bloating

Owl body b/c 2 nuclei

can see trophozoites in stool

treat w/ metronidazole

Question 6

What are the important things to know about entamoeba histolytica?

Answer 6

causes amebiasis
bloody diarrhea
liver abscess-anchovy paste, flask-shaped ulcer, RUQ pain
have multiple nuclei

Question 7

What are the important things to know about cryptosporidium?

Answer 7

causes severe diarrhea
oocysts that are acid fast
nitazoxanide used to treat

Question 8

What causes bacterial dysentery? What causes bloody diarrhea protozoal?

Answer 8

bacterial dysentery: shigella

protozoal dysentery: entamoeba histolytica

Question 9

Cryptococcus causes what? Cryptosporidium causes what?

Answer 9

cryptococcus–meningitis

cryptosporidium–severe diarrhea

Question 10

What are the important things to know about toxoplasma gondii?

Answer 10

AIDS: ring-enhancing lesion
found in meat, cat feces, crosses placenta
congenital toxoplasmosis

Question 11

What are the features of congenital toxoplasmosis?

Answer 11

chorioretinitis
hydrocephalus
intracranial calcifications

Question 12

What is the treatment for toxoplasma?

Answer 12

sulfadiazine
pyrimethamine
folinic acid

Question 13

WHat do you need to know about naegleria fowleri?

Answer 13

Nalgene-filled w/ fresh water
swimming in fresh water lakes
Naegleria enters cribriform plate–>meningoencephalitis

Question 14

HOw do you treat naegleria fowleri?

Answer 14

amphotericin B

Question 15

What are the important things to know about African Sleeping Sickness?

Answer 15

Trypanosoma brucei rhodesiense + gambiense
enlarged lymph nodes, fever, somnolence, coma, encephalitis

spread by tsetse fly

treated w/ suramin and melarsoprol (CNS penetration)
Sure is nice to sleep. Melatonin helps you sleep.

Question 16

What are the important things to know about malaria?

Answer 16

Plasmodium Vivax/Ovale-tertian 48 hour cycle. dormant form in liver (hypnozoite).
Plasmodium malaria–72 hour cycle, quartan
Plasmodium Falciparum–most severe, occlude capillaries in brain, kidney, lungs.

Question 17

Which bug spreads malaria?

Answer 17

Anopheles mosquito

Question 18

When do you see schuffner stippling?

Answer 18

red granules seen in malaria seen in RBC cytoplasm of P vivax/ovale

Question 19

What’s the deal with babesiosis?

Answer 19

northeastern US–ixodes tick
fever and hemolytic anemia
see Maltese cross and ring form on blood smear

Question 20

What is the treatment for basesiosis?

Answer 20

atovaquone + azithromycin

quinine + clindamycin

Question 21

What causes chagas disease?

Answer 21

Trypansoma Cruzi
Everything gets big!
cardiomyopathy
megacolon
megaesophagus
found in South America
**sometimes unilateral periorbital swelling (romana sign)

spread by reduviid bug (kissing bug)

Question 22

What are the important features of Leishmania donovani?

Answer 22

causes visceral and cutaneous leishmaniasis
spread by sandfly
see macrophages w/ amastigotes (lack flagella)

Question 23

What are the features of visceral leishmaniasis?

Answer 23

spiking fevers
HSM
pancytopenia

Question 24

What is the treatment for leishmaniasis?

Answer 24

Amphotericin B–visceral

Sodium stibogluconate for cutaneous

Question 25

What are the important features of trichomonas?

Answer 25

foul-smelling
flagellated
vaginal itching
greenish discharge
increases vaginal pH
see trophozoites on wet mount
get strawberry cervix
treated w/ metronidazole.

Question 26

Which protozoa are spread this way? 
sandfly
reduviid bug
ixodes tick
tsetse fly
anopheles mosquito?

Answer 26

sandfly--leishmaniasis
reduviid bug--trypansoma cruz (chagas)
ixodes tick-Lyme dx and babesiosis
tsetse fly-trypansoma brucei
anopheles mosquito-malaria