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avian & livestock assay data sheet
Dientamoeba fragilis
Test
code:
X0046
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Ultrasensitive qualitative detection of
Dientamoeba
fragilis by polymerase chain reaction.
Dientamoeba fragilis is a single-celled
protozoan parasite that infects the human
gastrointestinal tract and can also infect pigs,
primates and other mammals. It is a flagellated
protozoan closely related to trichomonads, and
unlike many intestinal parasites, it lacks a
cyst stage, existing only in its trophozoite
form. This organism is found worldwide; its
prevalence can be from 0% to over 80% depending
on the geographic location, group studied, and
diagnostic methods used.
It is debated whether this parasite is a harmless commensal or a mild
pathogen. Studies have shown that this parasite
is frequently detected in both symptomatic and
asymptomatic individuals, with prevalence rates
varying widely (0.2%–19% in general populations,
but higher in specific groups like children in
day care). Symptoms associated with this
parasite, such as abdominal pain, diarrhea,
bloating, and fatigue, are non-specific and can
overlap with those of many other
gastrointestinal conditions, making causation
hard to establish. Additionally,
D.
fragilis does not invade tissues, lacks a
cyst stage for easy transmission or survival
outside the host, and is often found alongside
other potential pathogens like pinworms (Enterobius
vermicularis) or
Blastocystis parasites, which could be the
true culprits behind symptoms. Furthermore,
antibody prevalence in healthy populations is
very high, and carriers of this parasite do not
seem to develop any chronic complications. These
findings tend to support this parasite being a
commensal.
D. fragilis spreads primarily
through the fecal-oral route, often via contaminated food,
water, or close contact with infected individuals. It may also
be transmitted through pinworm eggs (Enterobius
vermicularis), as the two parasites frequently co-infect
(Girginkardeşler et al., 2008). Effective hygiene practices such
as handwashing and proper sanitation are key to prevention.
Diagnosis is often by microscopic examination of fecal smears. However,
the sensitivity and specificity of this method are low because
the parasite is almost invisible in stool and is very fragile.
PCR is increasingly being used to replace traditional methods,
due to its high sensitivity and specificity (Stark et al., 2006;
Tolba et al., 2022).
Utilities:
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Help confirm the disease causing agent
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Environmental monitoring
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Help ensure that individual mammals are free of
this parasite
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Early prevention of spread of this parasite in herds and
animal facilities
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Minimize human exposure to this parasite
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Safety monitoring of biological products and vaccines
that derive from
susceptible
mammals
References:
Girginkardeşler N, Kurt O, Kilimcioğlu AA, Ok UZ.
Transmission of Dientamoeba fragilis: evaluation
of the role of Enterobius vermicularis.
Parasitol Int. 2008 Mar;57(1):72-5.
Stark D, Beebe N, Marriott D, Ellis J, Harkness J.
Evaluation of three diagnostic methods, including real-time PCR,
for detection of Dientamoeba fragilis in stool specimens. J Clin
Microbiol. 2006 Jan;44(1):232-5.
Tolba MM, Allam AF, Khalil SS, Elshouki WM, Shehab
AY. Evaluation of microscopy and PCR for detection of
Dientamoeba fragilis. Trop Parasitol. 2022 Jul-Dec;12(2):87-93.
Specimen requirements:
0.2 ml feces or fecal swab, or environmental
swab, or 0.2 ml cell culture.
Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.
For all specimen types, if there will be a delay
in shipping, or during very warm weather,
refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping
requirements are specified. Frozen specimens
should be shipped so as to remain frozen in
transit. See shipping
instructions for more information.
Turnaround time:
2 business days
Methodology:
Qualitative real time PCR
Normal range:
Nondetected
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