Protozoa Flashcards
Entamoeba histolytica
“Phagocytosis of RBCs
Transmission: Cysts in water
Occurs in colon
Human pathogen”
“Disease: Amoebic dysentery, liver abscess (““anchovy paste”” exudate), RUQ pain (histology shows flask-shaped ulcer if submucosal abscess of colon ruptures)
Diagnosis: serology and/or trophozoites (with RBCs in the cytoplasm) or cysts (with multiple nuclei) in stool”
Giardia lamblia
“Face.
Transmission: Cysts in water
Occurs in small intestine
Human + animal (beavers) pathogen”
“Camping, gas-diarrhea. Drinking contaminated fresh water.
Disease: Giardiasis - bloating, flatulence, foul-smelling, fatty diarrhea (often in campers/hikers)
Diagnosis: Trophozoites or cysts in stool”
Cryptosporidium
“Animal pathogen.
Transmission: cysts in water
Human + animal pathogen “
“Disease: severe diarrhea in AIDS; mild disease (watery diarrhea) in nonimmnocompromised
Diagnosis: cysts on acid-fast stain”
Trichinosis vaginalis
“Pear shapped protozoan with flagella in vaginal discharge
Transmission: sexual (can’t exist outside human b/c it can’t form cysts)”
“STD
Disease: Vaginitis - foul-smelling, greenish discharge; itching and urning
Diagnosis: trophozoites (motile) on wet mount”
Trypanosoma cruzi: Heart
Transission: Reduvic bug (“kissing bug”), a painless bite
“Reduvig bug, Kissing bug. Chagoma, CHF
Disease: Chagas’ disease: dilate cardiomyopathy, megacolon, megaesophagus, predominantly in South america; swollen lymph nodes, CHF
Diagnosis: Blood smear”
Trypanospoma gambiensis (W Africa) and rhodesiense (E Africa): Brain
Transmissio: Tse-tse fly, painful bite
“CNS infection.
Disease: African sleeping sickness: enlarged lymph nodes, recurring fever (due to antigenic variation); somnolence, coma; encephalitis
Diagnosis: Blood smear”
Leshmania donovani
“Transmission: Sandfly
Flagellated, cause ulcers”
”
Disease: Visceral leishmaniasis (kala-azar): spiking fevers, hepatosplenomegaly, pancytopenia
Diagnosis: Macrophaes containing amastogotes”
Plasmodium
Transmission: Anopheles Mosquito
” Disease: Malaria (fever, headache, anemia, splenomegaly)
Vivax/ovale: 48-hour cycle (tertian; includes fever on first day and third day, thus fevers are actually 48 hr apart); dormant form (hypnozoite) in liver
Falciparum: severe; irregular fever patterns; parasitized RBC occlude capillaries in brain (cerebral malaria), kidneys, lungs: multiply infect RBC’s
Malariae: 72 hour cycle (quartan)
Diagnosis: blood smear, trophozoite ring form, RBC schizont with merozoites “
Toxoplasma gondii
“Tachyzoites-bradyzoites
Transmission: cysts in meat or cat feces, crosses placenta “
“Ingest oocysts in cat feces
Disease: brain abscess in HIV (seen as ring-enhancing brain lesions on CT/MRI)
Congenital toxoplasmosis: classic traid of chorioretinitis, hydrocephalus, and intracranial calcifications
Diagnosis: Serology, biopsy
“
Naegleria, Acanthamoeba
Transmission: swimming in freshwater lakes; enters via cribriform plate
“Disease: Rapidly fatal meningoencephalitis
Diagnosis: amoebas in spinal fluid “
Babesia microti
Transmission: Ixodes tick (same as Borrelia burgdorferi of Lyme diesease; may often coinfect humans)
Disease: Babesiosis: fever and hemolytic anemia; predominantly in northeastern U.S.; aspelania increases risk of severe disease
Balentidium Coli
the only ciliated protozoan that causes human disease-> diarrhea
Isospora
GI infection in immunosuppressed
Pneumocystic carinii
Human reservoir
Pneumonia
