Protozoa 3/2/09

Front 1

24 yo (obnoxious) female working on the Amazon develops diarrhea that contains blood and mucous. Stool sample shows cyst with one nucleus.
1. Dx?
2. Transmission
3. Life cycle/location in body
4. Dz w/ S&S
5. Dx
6. Tx

Back 1

1. Entamoeba Histolytica
2. Cysts in water
3. Ingested cysts --> implant in large intestine --> cysteine proteases & phoslipase A --> tissue damage --> can met to liver --> liver abscess
-eggs released in feces
4. Amoebic Dysentery: bloody diarrhea, RUQ pain, flask shaped colonic ulcers, amebomas;
Liver Abscess
5. Trophozoites (contain RBCs) and cysts (1-4 nuclei) in stool; serology (80%)
6. Metronidazole & Iodoquinol

Front 2

45 yo male 2 weeks after trip in Colorado complains of abdominal pain, cramping, and bloating. Occasional foul smelling, steatorrheic diarrhea. Cyst with 4 nuclei found in stool.
1. Dx
2. Transmission
3. Life cycle
4. Dz
5. Dx
6. Tx

Back 2

1. Giardia Lamblia
2. Ingested cysts - water or food, resistant to chlorine (boil or filter); campers/hikers, daycares
3. Cysts excyst from stomach acid--> adhere to Duodenal or Jejunal mucosa (inflammation, crypt hypertrophy, villous flattening -->villous atrophy & severe malabsorption) --> cysts released in feces
4. Most asymptomatic; Giardiasis: flatulence, bloating, foul-smelling diarrhea - steatorrheic (acute or chronic)
5. Dx: Cysts (2-4 nuclei) or trophozoites (heart shaped, 2 nuclei, 4 pairs flagella) seen in stool - 3x on 3 different days; Duodenal aspirates (string test); Elisa or IF of stool (sens & spec)
6. Metronidazole

Front 3

Physician in Milwuakee notices that almost every patient visit over the past two weeks has complained of mild, intermittent watery diarrhea. One patient has returned today because of severe diarrhea that immodium and a 10 day course of antibiotics have not cured.
1. Likely Dx - what lab would you order?
2. Transmission
3. Life cycle
4. Dz
5. Dx
6. Tx

Back 3

1. Cryptosporidium parvum - AFS
2. Ingested oocysts in water supply, large outbreaks; cyclospora - sporadic outbreaks (guatemalan raspberries)
3. Oocysts --> release sporozoites --> invade lower small bowel (ileum) --> mature asexually = merozoites --> infect other epithelial cells --> sexually replicate in vacuole --> infective oocysts in feces.
4. Mild, intermittent diarrhea, intractable diarrhea in AIDS (immunocomp) patients
5. Acid Fast Stain of stool shows Oocysts w/ 4 sporozoites (Cyclospora are larger); immunoassays
6. Bactrim (trimethoprim/sulfamethoxazole)

Front 4

22 yo college student presents to student health complaining of vaginal burning and itching. Pelvic exam demonstrates yellow-cream colored vaginal discharge. Quick wet mount gives you the diagnosis.
1. Diagnosis?
2. Transmission
3. Life cycle
4 Dz
5. Dx
6. Tx

Back 4

1. Trichomonas Vaginalis
2. STD (STI if you're PC)
3. Trophozoite infects vagina, vulva, cervix or urethra via fluid secretions --> trophozoite undergoes binary fission (5-28 day incubation); male urethra --> seminal vessicles and prostate
4. Vaginitis: foul smelling yellow to cream colored discharge (FA says green), microulceration, inflammation, erosion, local tenderness, burning and itching
5. Wet mount shows motile trophozoite (pear shaped, undulating membrane, four flagella)
6. Metronidazole (patient and all partners)

Front 5

27 yo med student doing research in Uganda develops paroxysms of chills and high fever. He has had 2 events since it began 6 days ago. Spleen is palpable.
1. Dx
2. Transmission
3. Life cycle
4. Dz
5. Dx
6. Tx

Back 5

1. Malaria - Plasmodium Malaria (every 72 hours)
2. Mosquito (Aegyptes)
3. Mosquito injects sporozoites ---> infect & replicate in liver --> Merozoites released --> infect RBCs --> asexually replicate to create shizonts or form gamets to create micro and macrogametocytes --> RBCs lyse --> mosquito ingests micro & macrogamets --> fuse to zygote --> replicate to sporozoites in salivary gland
4. Malaria - 2-3 day fever paroxysms, anemia, hepatosplenomegaly, depressed bone marrow, jaundice, hemoglobinuria (black water), hypotension, tachycardia.
Falciparum - cerebral malaria
Malariae - glomerulonephritis
Vivax/Ovale - hypnozoites in liver = chronic dz
Dx: Asexual stages on blood film (sporozoites, merozoites, micro/macrogametes)
Tx:Chloroquine, (primaquine for chronic), sulfadione + pyrimethamine, mefloquine, quinine