parasitology - flagellates and ciliates

giardia lamblia

most common intestinal protozoan in the US, located worldwide and associated with day care centers, campers, and skiiers

giardia lamblia

host: human, beaver, dog, wild game

no intermediate host

giardia lamblia

diagnostic stage: cysts in feces, trophs in feces or duodenal contents

infective stage: cysts in fecally contaminated food and water, fecal oral route

giardia lamblia

troph: bilaterally symmetric, 2 anterior nuclei and 8 flagella, sucking disc, 2 median bodies, 2 axonemes (intracellular), multiply asexually

giardia lamblia

cyst: formed in lumen under influence of bile, broadly oval, 2-4 nuclei, central axoneme (old man with glasses), cytoplasm pulled away from cell wall

giardia lamblia

there is a kit available for this antigen, PCR

giardia lamblia

symptoms: irritation from attachment, interference with absorptive function of gut, inflammation and flattening of villi, abdominal pain, flatulence, fatty diarrhea, foul smelling stool

malabsorption of fat, lactose, and vitamins A and B12 (weight loss), lactose intolerance, vitamin deficiencies

giardia lamblia

treatment: metronidazole, tinidazole, furazolidone, paromomycin

dientamoeba fragilis

associated with mild diarrhea, some abdominal pain, located worldwide, association with enterobius vermicularis

dientamoeba fragilis

troph: cecum and colon, multiply asexually, amebalike with no flagella, 1-2 nuclei

dientamoeba fragilis

no cyst stage

diagnostic stage: trophs in feces, hematoxylin smear

infective stage: trophs in fecally contaminated food or water, pinworm eggs

dientamoeba fragilis

symptoms: asymptomatic, irritation of mucosa (mild diarrhea, anorexia, abdominal pain)

dientamoeba fragilis

treatment: iodoquinol, paromomycin, tetracycline

chilomastix mesnii

troph: large intestine, pear shaped, pinched off tail that is curved, cystostome is the mouth, 3 anterior flagella and 1 trailing flagella

chilomastix mesnii

cyst: smaller and lemon shaped with a clear knob at the anterior end

trichomonas vaginalis

causes trichomonad vaginitis, trichomoniasis, urethritis

trichomonas vaginalis

diagnostic stage: trophs in urethral discharge, vaginal smear, urine

infective stage: trophs during sexual intercourse

trichomonas vaginalis

troph: long and broadly oval, long axostyle, short undulating membrane and costa that extends about one half of the body, no cyst stage

trichomonas vaginalis

female symptoms: vaginal inflammation, creamy to yellowish frothy discharge, burning urination, itching, irritation

male symptoms: asymptomatic, prostatitis, urethritis, epididymitis with hematuria, incomplete bladder emptying, WBC and RBC in urine

trichomonas vaginalis

treatment: metronidazole, tinidazole

balantidium coli

only ciliate and largest protozoan to infect humans, causes balantidiasis, balantidial dysentery, identical ciliate in pigs

balantidium coli

diagnostic stage: cyst and troph in feces

infective stage: cyst in fecally contaminated food and water

balantidium coli

troph: large intestine, multiply by binary fission, covered in cilia, cytostome, large kidney shaped macronucleus, small micronucleus

balantidium coli

cyst: round, 1 macronucleus, 1 micronucleus, cytoplasm may be pulled away from the cyst wall

balantidium coli

symptoms: asymptomatic, associated with abdominal discomfort with mild to moderate chronic recurrent diarrhea or acute dysentery, deep intestinal ulcers

balantidium coli

treatment: tetracycline, iodoquinol, metronidazole