[DISCUSSION] MODULE 2 UNIT 3 Flashcards
INTESTINAL FLAGELLATES
- Giardia lamblia
- Dientamoeba fragilis
- Chilomastix mesnili
- Pentatrichomonas hominis
ATRIAL FLAGELLATES
- Trichomonas vaginalis
- Trichomonas tenax
HEMOFLAGELLATES
- Leishmania spp.
- Trypanosoma spp.
Giardia lamblia Also known as
Giardia duodenalis, or Giardia intestinalis
manifests as a significant but not life-threatening gastrointestinal
disease
Giardia lamblia
resistant forms and are responsible for transmission of giardiasis
Giardia lamblia Cysts
infective stage
Giardia lamblia Cysts
hardy and
can survive several months in
cold water
Giardia lamblia mature cysts
occurs in the small
intestine.
Excystation Giardia lamblia
multiply by longitudinal binary fission, and remain in the duodenum and upper jejenum
Giardia lamblia Trophozoites
occurs when the trophozoite transits to the colon
Giardia lamblia Encystation
occurs when the host ingests food or water contaminated with the mature cysts
Infection with G. duodenalis
Depending on the strain involved, infection can occur with one ingesting as few as 10 cysts.
Giardia lamblia
Giardiasis in about half of the infected patients may be
Asymptomatic
- occurs in 1 to 4 weeks (average of 9 days)
Giardiasis
Symptomatic infection. Acute phase
- patients experience abdominal pain, described as cramping, associated with diarrhea.
Giardiasis
Symptomatic infection. Acute phase
- There is also excessive flatus with an odor of “rotten eggs” due to hydrogen sulfide.
Giardiasis
Symptomatic infection. Acute phase
- Other clinical features include abdominal bloating, nausea, and anorexia. Spontaneous recovery occurs within 6 weeks in mild to moderate cases.
Giardiasis
Symptomatic infection. Acute phase
- In untreated cases, patients may experience diarrhea with varying intensities, for weeks or months. The acute phase is often followed by chronic phase.
Giardiasis
Symptomatic infection. Chronic phase
- Characterized by steatorrhea
Giardiasis
Symptomatic infection. Chronic phase
- In some cases, periods of diarrhea have been observed to alternate with normal or even constipated bowel periods. There may be weight loss, profound malaise, and low-grade fever.
Giardiasis
Symptomatic infection. Chronic phase
Giardia lamblia trophozoite does not invade the tissue, but remains adhered to intestinal epithelium by means of the sucking disc.
Cytoadherence
It is able to cause alterations in the villi such as villous flattening and crypt hypertrophy.
Cytoadherence
These alterations lead to decreased electrolyte, glucose, and fluid absorption, and cause deficiency enzymes such as disaccharidases.
Cytoadherence
This results in the entire surface of the parasite being covered with (?) which help the parasite in evasion of host immune system.
variant-specific surface proteins (VSSPs)
Giardia lamblia Transmission
Fecal-oral route.
Transmission depends on the swallowing of mature cysts in fecally-contaminated food or water or by direct contact related to poor personal hygiene or sexual practices.
Giardia lamblia
The risk factors that favor survival and transmission are the same as those affecting amoebiasis
Giardia lamblia
Geographical distribution: Cosmopolitan. Endemicity is very high in areas with low sanitation, especially tropics and subtropics.
Giardia lamblia
Prevalence: Approximately 1.6 to 22% in the Philippines.
Giardia lamblia
Reservoir: Human, beavers, dogs, cats, and sheep serve as reservoirs
Giardia lamblia
was previously considered as an amoeba but has now been reclassified as an amoeboflagellate, based on electron microscopic study and antigenic similarity to Trichomonas
Dientamoeba fragilis