protozoa and parasites quick quiz Flashcards
Organism in which parasite lives
host
Host which maintains the parasite in nature as a source for continued transmission
resevoir
Host in which sexual reproduction takes place
definitive host
Host in which development occurs, possibly asexual reproduction, but not sexual reproduction
intermediate host
Host in which parasite cannot complete life cycle (dead-end)
accidental host
what egg morphology
which location?
S. mansoni
Africa, Middle East, Suriname, Brazil, Venezuela
which egg form?
what disease caused?
where?
S. haematobium - bladder granulomas, hematuria, associated with bladder cancer.
Africa, Middle East
which form?
what disease caused?
where found?
China, Indonesia, the Philippines
S. japonicum - periportal fibrosis, portal hypertension with hepatosplenomegaly. Hypersensitivity to eggs major cause of pathology. Eosinophilia common
life cycle of entaemoeba histolytica
- Mature cysts are ingested in fecally contaminated food, water, hands
- Excystation occurs in small intestine
- Released trophozoites migrate to large intestine
- Trophozoites produce cysts, passed in feces - can survive outside the body
- Can have (A) asymptomatic infection, (B) intestinal disease, or (C) extra-intestinal abscesses
anchovie paste absess?
entamoeab histolytica life cycle
morphology of entamoeba histolytica
morphology?
what do the cysts look like?
what do the trophozites look like?
signs and symptmoms?
pathology: buzz word here
dx:
rx: what do you use for sympotmatic infection? how about to eradicate luminal carriage?
- *Morphology:** Trophozoite (active form) - single nucleus, often contains ingested RBCs.
- *Cyst:** Excreted, durable form. May contain up to 4 nuclei
Signs & Symptoms: Acute- dysentery with abdominal pain. Chronic- recurrent episodes with blood and mucus in feces. Can disseminate to liver, lung, brain - forms abscesses
Pathology: Flask-shaped ulcers in large intestine. No protective immunity
Dx: Symptoms, history, and epidemiology - lab looks for cysts in stool; serology, Amoeba antigen and DNA [PCR] tests
Rx:** **Metronidazole for symptomatic infection, Paromomycin for eradication of luminal carriage
where do outbreaks of N. fowleri occur?
waht do you use to tx?
Outbreaks of N. fowleri have been associated with diving in fresh water and use of tapwater in neti pots
Amphotericin B is effective against N. fowleri in vitro, but the prognosis remains bleak for those that contract PAM, and survival remains less than 1%.
what is the morphology of trichomoniasis?
symptoms in men and wmen?
pathology: buzzword
dx: ?
rx?
Morphology: Trophozoite, single nucleus, 4 anterior flagella. Undulating membrane, symmetrical axostyle. No cyst form.
Symptoms: Asymptomatic in men (can transmit). In women, prefers pH >4.5, with copious, frothy discharge.
Pathology: Contact-dependent, vaginal epithelium damage, strawberry cervix
Dx: Clinical suspicion confirmed by finding trophozoites in discharge - PCR
Rx: Metronidazole. Safe sex practice is prophylactic
what is the life cycle of t. vaginalis?
what life cycle lacking?
- Organism resides in female lower genital tract and male urethra
- Multiplies by binary fission (mainly in female genital tract) - no cyst stage.
- Transmitted by sexual contact. Does not survive outside of the host, no known reservoir hosts.
who gets giradia?
morpohlogy?
symtpoms?
dx:
tx?
Epidemiology: World-wide distribution. Most common protozoan intestinal disease in US-often transmitted via water, also common in day care centers
Morphology: Flagellated protozoan. Trophozoite with 2 nuclei and bilateral symmetry of axostyles and suction discs. Cyst with 4 nuclei and a well-defined wall
** Symptoms:** Uncontrollable flatulence, abdominal distension, foul-smelling, bulky diarrhea. Stool often contains excess lipids, but rarely blood or necrotic tissue. Trophozoites cover and flatten intestinal epithelium, may lead to malabsorption of nutrients.
- *Dx:** Symptoms, history, epidemiology - find cysts and trophs in stool
tx: Treatment: Metronidazole