protozoa Flashcards
Parasites are divided to
- Protozoa
2. Helminthes
Helminthes are divided to
- Nematodes (roundworms)
- Cestodes (tapeworms)
- Trematodes (flukes)
Protozoa infections are divided to
- GI infections
- CNS infections
- Hematologic infections
- other infections (visceral infections and STD)
Protozoa GI infections - bugs and diseases
- Giardia lamblia - giardiasis
- Entamoeba histolytica - amebiasis
- Cryptosporidium - diarrhea
Giardia lamblia - disease and symptoms
Giardiasis: 1. bloating 2. flatulence
3. foul smelling, fatty diarrhea
Giardiasis is often seen in
campers/hikers
Giardia lamblia - transmission
cysts in water
Giardia lamblia - diagnosis
multinucleated trophozoites or cysts in stool
trophozoite?
a growing stage in the life cycle of some sporozoan parasites, when they are absorbing nutrients from the host. (pathogenic state)
Giardiasis - treatment
metronidazole
Entamoeba histolytica - disease and symptoms
Amebasis: 1. bloody diarrhea (dysentery)
- liver abscess (anchovy paste exudate)
- RUG pain
amebiasis - gross appearance
flask-shaped ulcer in colon
Entamoeba histolytica - rout from colon to liver abscess
invades through the intestinal wall to enter to the bloodstream
anchovy paste exudate
Amoebic abscesses of the liver produce brownish pus, which is described as looking like “anchovy paste”
Entamoeba histolytica - transmission
cysts in water
Entamoeba histolytica infection - diagnosis
- serology and/or
- trophozoites with RBCs in the cytoplasm
or cysts with up to 4 nuclei in stool
Entamoeba histolytica infection - treatment
- metronidazole
2. iodoquinol for asymptomatic cyst passers
Cryptosporidium - disease and symptoms
severe nonbloody diarrhea in AIDS Mild disease (watery diarrhea) in immunocompoment
Cryptosporidium - transmission
oocysts in water
Cryptosporidium - diagnosis
oocysts on acid-fast stain
Cryptosporidium - treatment/prevention
prevention by filtering city water supplies
notazoxamide in immunocompetent hosts
no clear treatment for AIDS patient
Protozoa - CNS infection - bugs and diseases
Toxoplasma gondi - toxoplasmosis
Naegleria fowleri - rapidly fatal meningoencephalitis
Trypanosoma brucei - African sleeping disease
Toxoplasma gondi infection and symptoms
- Congenital toxoplasmosis –> classic triad of chorioretinitis, hydrocephalus, intracranial calcification
- reactivation in aids –> brain abscess
Toxoplasma gondi transmission
cysts in undercooked meat (MC)
oocysts in cat feces
crosses placenta
Toxoplasma gondi - pregnant women should
avoid cats
Toxoplasma gondi - diagnosis
serology
biopsy (tachyzoite)
CT/MIR ring-enhancing lesion
Toxoplasma gondi in AIDS - CT/MIR
ring-enhancing lesion
Toxoplasma gondi infection - treatment
sulfadiazine + Pyrimethamine
Trypanosoma brucei - subspecies
- Trypanosoma brucei rhodesiense
2. Trypanosoma brucei gambiense
Trypanosoma brucei - disease and symptoms
African sleeping disease: 1. enlarged lymph nodes
2. recurring fever 3. somnolence 4. Coma
Mechanism of recurring fever in African sleeping disease
antigenic variation
African sleeping disease - transmission
Tsetse fly, a painful bit
African sleeping disease - diagnosis
Trypomastigote in blood smear