U3.1 - Intestinal and Urogenital Flagellates Flashcards
Flagellates:
Phylum
Phylum Sarcomastigophora/ Metamonada
Flagellates:
Subphylum
Subphylum Mastigophora
Flagellates:
Class
Class Zoomastigophora
Class Zoomastigophora:
kinds of species
- intestinal and urogenital flagellates
- hemoflagellates
Intestinal/ Urogenital flagellates:
habitat
large intestine; except:
1. Giardia duodenalis (small intestine)
2. Trichomonas vaginalis (urogenitals)
3. Trichomonas tenax (mouth)
Intestinal/ Urogenital flagellates:
formation/ rupturing of cyst
All undergo encystation; except:
Trichomonas species (trophozoite)
Intestinal/ Urogenital flagellates:
types of parasite
All are commensals; except:
1. Giardia duodenalis
2. Dientamoeba fragilis
3. Trichomonas vaginalis
Giardia duodenalis:
other names
Giadia intestinalis
Giardia lamblia
Cercomonas intestinalis
Giardia duodenalis:
MOT
ingestion of infective cysts
Giardia duodenalis:
causative agent of?
- Giardiasis
- Traveller’s Diarrhea
- Backpacker’s Diarrhea
- Beaver Fever
Giardia duodenalis:
pathogenesis
- Parasite attaches to the intestinal cells via an adhesive sucking disc located on its ventral side
- Once attached, the parasite causes villous flattening and crypt atrophy
Giardia duodenalis:
symptomatic or asymptomatic
Half of the patients:
may be asymptomatic
Giardia duodenalis:
acute cases
- excessive flatus with rotten egg (due to hydrogen sulfied) odor
- diarrhea
- malaise
- abdominal pains
- anorexia
Giardia duodenalis:
chronic cases
- steatorrhea
- weight loss
- profound malaise
- low-grade fever
Giardia duodenalis:
diagnosis
- DFS
- concentration techniques: cysts
- duodenal-jejunal aspiration
- enterotest
- antigen detection test (CWP1)
- direct fluorescent Ab test
Giardia duodenalis:
treatment
- metronidazole
- alternative drugs:
- tinidazole
- furazolidone
- abendazole
Giardia duodenalis:
epidemiology
- prevalent worldwide
- areas with poor sanitation and poor hygiene
- direct oral-anal sexual contact among MSM increase the risk
Giardia duodenalis:
prevention and control
- proper or sanitary disposal of human excreta
- normal water chlorination will not affect cysts, but usual water treatment modalities should be adequate
Dientamoeba fragilis:
originally described as?
ameba
Dientamoeba fragilis:
stages present
trophozoite
cyst
Dientamoeba fragilis:
nuclei:
peripheral chromatin:
karyosome:
nuclei: 1 or 2
peripheral chromatin: no PC
karyosome: 4-6 discrete granules
Dientamoeba fragilis:
MOT
fecal-oral route or via transmission of helminth eggs (E. vermicularis)
Dientamoeba fragilis:
symptomaticity
usually asymptomatic
Dientamoeba fragilis:
common symptoms
intermittent diarrhea with excess mucus
Dientamoeba fragilis:
diagnosis
- DFS
- not detected by concentration techniques
- prompt fixation of fresh stool with PVA fixative or Schaudinn’s fixative
Trichomonas vaginalis:
causative agent of?
trichomoniasis
Trichomonas vaginalis:
habitat
urogenital area
Trichomonas vaginalis:
MOT
- intimate contact
- infant delivery
- contaminated towels and underwear
Trichomonas vaginalis:
common symptoms
- vaginal discharge (green/ yellow color)
- vulvitis
- dysuria
- postpartum endometritis
- strawberry cervix (2% of the cases)
Trichomonas vaginalis:
male pathogenesis
asymptomatic
some cases: urethritis, prostitis
Trichomonas vaginalis:
diagnosis
- saline preparation of vaginal fluid
- culture: gold standard
- pap’s smear
- Ag detection
- PCR
Trichomonas vaginalis:
treatment
- metronidazole
- tinidazole
Trichomonas vaginalis:
epidemiology
- occurs worldwide
- high prevalence in greater sexual activity with multiple partners
Trichomonas vaginalis:
prevention and control
- reduce risk of exposure
- proper use of protective devices (condom, spermicidal foams)
- simultaneous treatment of infected sexual partners
- health and sex education
Non-pathogenic flagellates
- Pentatrichomonas (Trichomonas) hominis
- Trichomonas tenax
- Chilomastix mesnili