Parasites: Toxo, crypto, malaria

Question 1

Which 3 can be transmitted congenitaly

Answer 1

toxoplasmosis, chagas, malaria

Question 2

humans are what type of host for cyrpto, malaria, and toxo? (each)

Answer 2

toxo and plasmodium: intermediate host

cyrpto: definitive

Question 3

What is most deadly human parasite

Answer 3

plasmodium

Question 4

WHat are the 2 periodicities with malaria species and which is the “oddball”

Answer 4

vivax, ovale, falciparum - all tertian, or e/o day

malariae - every 3 days

Question 5

what is definitive host for malaria

Answer 5

anopheles mosquito

Question 6

malaria: What type of reproduction occurs within humans? what forms? where do they replicate? (2)

Answer 6

asexual reproduction
merozoites multiply (binary fission) in liver and RBCs

Question 7

Pathology of plasmodium falciparum death

Answer 7

causes RBCs to adhere and clog capillaries –> renal failure, pulmonary edema, etc

Question 8

Which species of malaria does not cause a relapsing disease?

Answer 8

falciparum does not relapse

Question 9

how is falciparum dx?

Answer 9

banana-shaped gametocytes or rings inside RBCs on blood smear

Question 10

What is a powerful tx for malaria

Answer 10

artemisinin

Question 11

What is the 2 drugs for traveler prophylaxissi for malaria

Answer 11

chloroquine

mefloquine

Question 12

What is the MC human parasitic infx? where is it found

Answer 12

toxoplasma: found where cats are kept as pets

Question 13

definitive host of toxoplasma

Answer 13

cat

Question 14

WHat 3 ways can humans contract toxo?

Answer 14

• cat feces- oocytes ingested
• tissue cysts: by eating meat of other intermediate hosts. (pork, lamb, venison)
• congenital infx

Question 15

Where does toxo replicate within humans

Answer 15

macrophages (intracellular replication)

Question 16

Where do toxo cysts form and remain in humans

Answer 16

CNS and retina

Question 17

what percentage of toxo infx are asx?

Answer 17

80-90%

Question 18

What type of toxo infx is most serious and MC symptomatic

Answer 18

congenital

Question 19

What are sx of congenital toxo infx? (3)

Answer 19

chorioretinitis, intracranial calcifications, hydrocephalus

Question 20

What is the 2 most frequently dx parasite in human feces

Answer 20

E.histolytica and cryptosporidium

Question 21

What is transmission for crypto? (3)

Answer 21

fecal-oral: food-borne, water-borne, swimming pools

Question 22

What form of crypto attaches to humans? What form does it mature into? where does this occur

Answer 22

sporozoites attach to intestines and mature in to trophozoites in jejunum

Question 23

What happens to crypto trophozoites in the jejunum

Answer 23

they are engulfed by epithelial cells but remain on lumen side of cell

Question 24

how is crypto dx?

Answer 24

acid-fast oocytes in stool