Protozoa Flashcards
Giardia lamblia
p/w giardiasis
tranmission
dx
tx
giardiasis = bloating, flatulene, foul smelling fatty diarrhea
cyts in water
multinucleated trophozoites/ cysts in stool/antigen detection
metronidazole
Entamoeba histolytica
p/w amebiasis
transmission
dx
tx
amebiasis = bloddy diarrhea (dysentary), liver abscess & RUQ pain, flask shaped ulcers on colon bx
cysts in water
trophozoites with engulfed RBCs or up to 4 nuclei
serology or antigen
metronidazole
paromomycin or iodoquinol for asx cyts passers
Cryptosporidium
p/w
tranmission
dx
tx
Severe diarrhea in AIDS
mild watery diarrhea in immunocompetent
oocysts in water
oocyst on acid fast stain; antigen
immunocompetent - nitazoxanide
prevention
Toxoplasm gondii
p/w immunocompetent, reactivation in AIDS, congenital
tramission
dx
tx
immunocompetent - mononucleosis like syndrome w/ (-) monospot test
AIDS - brain abscesses - multiple ring enhancing lesions on MRI
congenital - IC calcifications, hydrocephalus, chorioretinitis
cysts in meat; oocysts in cat feces; crosses placenta
serology; bx (tachyzoite)
sulfadiazine + pyrimethamine
Naegleria fowleri
p/w
transmission
dx
tx
rapidly fatal meningoencephalitis
swimming in fresh water; enters cribiform plate
ameobas in CSF
amphotericin B; very fatal
Trypanosoma brucei
p/w African sleeping sickness
transmission
dx
tx
african sleeping sickness:
enlarged LNs, recurring fever, somnolence, coma
tsetse fly, painful bite
trypomastigote on blood smear
suramin - blood bourne dx
melarsoprol - CNS penetration
Plasmodium
p/w malaria
tranmission
dx
tx (general)
fever, H/A, anemia, splenomegaly
anopheles misquito
blood smear: trophozite ring form w/in RBC
schizont containing merozoites
chloroquine (blocks plasmodium heme polymerase)
if resistant: mefloquine or atovaquone/proguanil
if life threatening: IV quinidine or artesunate
(test for G6PD def)
Plasmodium vivax/ovale
cycle
blood smear
tx
48hr cycle:
dormant form/hypnozoite lives in liver
fever on 1st & 3rd days, 48hrs apart
red granules throughout RBC cytoplasm
*Schuffner staining
add primaquine for hypnozoite
Plasmodium falciparum
cycle
virulence
severe
irregular fever patterns
parasitized RBCs occlude capillaries in brain, kidney & lungs
Plasmodium malariae
cycle
72 hr cycle (quartan)
Babesia
p/w babesiosis
transmission
dx
tx
fever & hemolytic anemia (increased UCB)
in NE US
asplenia increased risk for sever dx
ixodes tick
blood smear: ring form, maltese cross
PCR
atovaquone & azithromycin
Trypanosoma cruzi
p/w Chagas dx
transmission
dx
tx
Chagas dx
= DCM w/ apical atrophy, megacolon, megaesophagus & u/l periorbital swelling in acute stage
triatomine bug (“kissing bug”) - deposites feces in painless bite
blood smear: trypomastigote
benznidazole or nifurtimox
Leishmania donovani
p/w visceral leishmaniasis, cutaneous leishmaniasis
transmission
dx
tx
visceral leishmaniasis
= spiking fevers, HSM, pancytopenia
cutaneous leishmaniasis
= skin ulcers
sandfly
blood smear: macrophages w/ amastigotes
amphotericin B, stibogluconate
Trichomonas vaginalis p/w vaginitis transmission dx tx
vaginitis
= foul smelling greenish d/c, vaginal inflammation, ph >4.5
itching, burning
STI
trophozoites on wet mount, strawberry cervix
metronidazole, tx partner
