Parasitology Flashcards
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
