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Flashcards in Parasitology Deck (20):

Protozoa GI infection

giardia lamblia, E. histolytica, cyrptosporidium


What disease is caused by giardia infection? Transmission? treatment?

giardiasis: bloating, flatulance, foul-smelling fatty diarrhea. often seen in campers and hikers.
transmitted by cysts in water
tx: metronidazole


What disease is caused by E. histolytica? transmission? treatment?

amebiasis: bloody diarrhea, liver abscesses (anchovy paste), RUQ pain with flash shaped ulcer if submucosal abscesses of colon rupture.
transmitted by cysts in water. tx: metronidazole. iodoquinol for asymptomatic cyst passers


Dx of Giardia

trophozoites or cysts in stool


Dx of E. histolytica

serology and/or trophozoites with RBCs in the cytopmaslm or cysts with up to 4 nuclei in the stool


What disease is caused by cryptosporidium? transmission? treatment?

severe diarrhea in AIDS. mild disease in immunocompetent. transmitted by oocysts in water. tx: prevention, nitazoxanide in immunocompetent


What are the CNS protozoa parasites?

toxoplasma gondii, naegleria fowleri, trypansoma brucei


Toxoplasma gondii: diseases

brain abscesses in HIV (ring enhancing). or, congenital infection: chorioretinitis, hydrocephalus, intracranial calcifications


transmission, dx, and tx of toxoplasma

cysts in meat or oocytes in cat feces. crosses placenta.
dx: serology or biopsy showing tachyzoite.
Tx: Sulfadiazine (folate inhibitor) with pyrimethamine


Naegleria fowleri: disease

rapidly fatal meningoencephalitis


Naegleria fowleri: transmission, diagonsis, and treatment

swimming in freshwater lakes. enters via cribiform plate
Dx: amoebas in spinal fluid
Tx: very few survivors, but try amphotericin B


Trypanosoma brucei disease

African sleeping sickness. casues relapsing/remitting fever d/t antigenic variation, LAD, somnolence, coma


Transmission of brucei disease

tsetse fly
dx: blood smear
tx: Suramin for blood-borne disease or melarsoprol for CNS penetration


Characteristics of malaria

fever, headache, anemia, splenomegaly


Differentiating btw P. vivax, ovale, falciparum, malariae

P. vivax/ovale: 48 hr cycle with dormant form in liver
P. falciparum- severe, irregluar fever patterns with parasitized RBCs occluding capallaries in the brain, kidneys, and lungs
P malariae: 72 hr cycle


Dx of malaria

blood smear showing trophozoite ring form within RBCs or schizont containing merozoites


Treamtnet for malaria

chloroquine, which blockes heme polymerase. if resistant, use mefloquine or atovaquone/proguanil
if life threatening, use qunidine after testing for G6PD deficiency
vivax and ovale: ad primaquine for the hypnozoite. test for G6PD deficiency


Babesia disease

fever and hemolytic anemia in NE US. Asplenia is a risk for severe disease


Babesia transmission

Ixodes tick (just like for lyme disease).


Dx and Tx for babesia

blood smear, ring forms or maltese cross. PCR. treat with atovaquone and azitrhomycin