Parasites: Toxo, crypto, malaria Flashcards
Which 3 can be transmitted congenitaly
toxoplasmosis, chagas, malaria
humans are what type of host for cyrpto, malaria, and toxo? (each)
toxo and plasmodium: intermediate host
cyrpto: definitive
What is most deadly human parasite
plasmodium
WHat are the 2 periodicities with malaria species and which is the “oddball”
vivax, ovale, falciparum - all tertian, or e/o day
malariae - every 3 days
what is definitive host for malaria
anopheles mosquito
malaria: What type of reproduction occurs within humans? what forms? where do they replicate? (2)
asexual reproduction merozoites multiply (binary fission) in liver and RBCs
Pathology of plasmodium falciparum death
causes RBCs to adhere and clog capillaries –> renal failure, pulmonary edema, etc
Which species of malaria does not cause a relapsing disease?
falciparum does not relapse
how is falciparum dx?
banana-shaped gametocytes or rings inside RBCs on blood smear
What is a powerful tx for malaria
artemisinin
What is the 2 drugs for traveler prophylaxissi for malaria
chloroquine
mefloquine
What is the MC human parasitic infx? where is it found
toxoplasma: found where cats are kept as pets
definitive host of toxoplasma
cat
WHat 3 ways can humans contract toxo?
- cat feces- oocytes ingested
- tissue cysts: by eating meat of other intermediate hosts. (pork, lamb, venison)
- congenital infx
Where does toxo replicate within humans
macrophages (intracellular replication)
Where do toxo cysts form and remain in humans
CNS and retina
what percentage of toxo infx are asx?
80-90%
What type of toxo infx is most serious and MC symptomatic
congenital
What are sx of congenital toxo infx? (3)
chorioretinitis, intracranial calcifications, hydrocephalus
What is the 2 most frequently dx parasite in human feces
E.histolytica and cryptosporidium
What is transmission for crypto? (3)
fecal-oral: food-borne, water-borne, swimming pools
What form of crypto attaches to humans? What form does it mature into? where does this occur
sporozoites attach to intestines and mature in to trophozoites in jejunum
What happens to crypto trophozoites in the jejunum
they are engulfed by epithelial cells but remain on lumen side of cell
how is crypto dx?
acid-fast oocytes in stool
