Protozoas

Question 1

Entamoeba Histolytica

transmission
pathogenesis
diagnosis
treatment

Answer 1

Cysts, contaminated food, water

Non-invasive
- mucosa surface, GI, ab pain

Invasive

• dysentery; blood and hence hematophagous
• perforation, colitis, peritonitis
• • Hematogenous mets
• – Liver, else where

Dx

• stools, sCOPE, Serology
• • stool useless for liver abscess

Metroniadazole

Question 2

Name 2 other species of entamoeba

Contrast the cyst and trophozoites of e histolytica and one of them

Answer 2

e. Coli and e. dispar

e. histolytica
- 4 nuclei
- hematophagous, central Karyosome
e. coli
- 8 nuclei
- eccentric Karyosome

Question 3

Another amoebAE name infection

Answer 3

Acantamoeba

- contact lens solution; amoebic keratitis

Question 4

Name intestinal flagellates

Pathology of one of them
- Shape, appearance

Answer 4

Giardia Intestinalis; trichomonas hominis

GI
- same Cyst, contaminated food, water
- GI stuff
WO bleeding
looks oval lmao

Question 5

Toxoplasmosis Gondii

• lifecycle
• transmission to humans

Answer 5

Cat poop – Cats are the definitive host

• • Adult stage + Sexual repro; others intermediate hosts are asexual repro
• Oocysts - Sporozoites

Infected tissue, food, rats
- Cysts - Bradyzoites

HUMAN, macrophage;
- Pseudocysts - Tachyzoites

Human can from cat poop or infected tissue or blood, transplants; vertically too

Question 6

Toxoplasmosis Gondii
Pathology
- congenital [4]
Lab

Answer 6

Fever, Eye lesions
- Encephalitis

Congenital

• ICC,
• Retinochoroiditis
• Hydrocephalus
• HSM

Lab dont do IgM - peak too long

Question 7

Contrast congenital

CMV, Toxo, Syphilis, Rubella

Answer 7

ICC
Retinochoroiditis
Hydrocephalus
HSM

ICC
can have retinochoroiditis too
CN8
HSM

Keratitis
CN8
Notched teeth
- Hutchinson’s triad

Rubella:

• Eye
• CN8
• CVS

Question 8

Malaria

• transmissions
• transmission cycle

Answer 8

Anopheles Mosquito; direct blood, needles, vertical, transfusion

Mosquito
- give Sporozoites

Human

• sporozoites go to LIVER grow to Trophozoites then Schizonts w Merozoites inside
• sporozoites go to LIVER to form Hypnozoites
• • only for P. Vivax and P. Ovale
• merozoites eat RBC
• Trophozoites can give Gametocytes;
• • mosquito take this

Question 9

Diagnosis method?

Differentiate

Answer 9

Microscopy Giemsa stain
- thick for presence; thin for species

Falciparum vs Vivax

• ring accole form, multiple in one RBC
• infected RBC is same size
• gametocyte is banana

vivax
- infected RBC is bigger; w schuffner’s dots (ovale also can)

note banded for p.malariae

Question 10

Another diagnosis method?

Answer 10

Dipstick

• HRP 2 antigen specific for Pf
• but got Pf without HRP 2

-pLDH (parasite LDH) for general plasmodium