 INTESTINAL PARASITES (Helminths)
NEMATODA Order: Oxyurata
ENTEROBIUS VERMICULARIS
oss1-ic
Enterobius vermicularis:
World-wide distribution with the highest prevalence
in temperate and cold climates
(fewer changes of clothing) and in crowded conditions.
Life cycle.
oss2-ic
Enterobius vermicularis:
gravid female worm.
ent_Gini-ic
Enterobius vermicularis:
adult worms.
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Courtesy of Dr. Gustavo A. Gini:
Quimico-Biologo, Microbiologist,
Bacteriology
Professor at University of del Valle of Guatemala
Former Chief of Microbiology Department and Director
of School of Chemical Biology University of San Carlos of
Guatemala. |
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Images of Adult worms of
E.vermicularis in the lumen of the appendix
Courtesy of
M.Lisci MD and G.Cera MD:
Pathology Unit,
Ospedale di Mondovì ASL 16 Mondovì, Italy. |
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E.vermicularis
are small nematodes; female are 8 to 13 mm by 0,3-0,5 mm; males
are 2-5 mm by 0,1-0,2 mm. The cuticle contains narrow lateral
alae (01-250,
02-250, 03-100,
08-250,
12-250, 16-100,
336Saygi-ic)
that extend most of the length of the body of the worm.
The oesophagus has a prominent muscular posterior bulb (04-250,
05-400). There are few somatic muscle cells in each
quarter of the worm(14-50,
02-250,
07-100, 08-250). |
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In the gravid female the uterus is distended with eggs (09-400,
10-100, 11-250,
11-400, 12-400) and occupies most of
the body cavity. Eggs measure 50-60 micron by 20-30 and are
flattened on one side; the shell is composed of two layers (11-400,
12-400). |
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Intestinal lesions are minimal and may include ulcers and mild
catarrhal inflammation (12-250,
13-100). |
14-50-ic
14-50: E.vermicularis:
transverse section of the adult worm in the lumen
of the appendix 50 X
H.E. stain
01-250-ic
01-250: E.vermicularis:
anterior end of the male worm: alae, Intestine,
testis and muscle cells are visible 250 X H.E. stain
02-250-ic
02-250: E.vermicularis: adult
worm 250 X H.E. stain
03-100-ic
03-100: E.vermicularis: adult worms 100 X H.E. stain
04-250-ic
04-250: E.vermicularis: adult worm; longitudinal section,
anterior end with oesophagus 250 X H.E. stain
05-400-ic
05-400:
E.vermicularis: adult worm; longitudinal section of
the anterior
end with oesophageal bulb 400 X H.E. stain
16-100-ic
16-100:
E.vermicularis: adult worm; longitudinal section
100 X H.E. stain
07-100-ic
07-100: E.vermicularis: adult worms in the granuloma
100 X H.E. stain
08-250-ic
08-250: E.vermicularis: adult worm; transverse section of
the anterior
end with esophagus 250 X H.E. stain
12-250-ic
12-250: E.vermicularis: transverse sections of adult worms
in a granuloma 250 X H.E. stain
13-100-ic
13-100: E.vermicularis: transverse sections of adult worms
in a granuloma 100 X H.E. stain
14-250-ic
14-250: E.vermicularis: adult female, transverse section
250 X H.E. stain
09-400-ic
09-400: E.vermicularis: transverse sections of gravid
female
with eggs 400 X H.E. stain
10-100 & 11-250-ic
10-100 &
11-250: E.vermicularis: transverse sections of
gravid female
with eggs 100X H.E. stain
11-400 & 12-400-ic
11-400 &
12-400:
E.vermicularis: eggs in transverse
sections
of gravid female 400x H.E. stain
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| 9oss-ic |
10oss-ic |
Enterobius vermicularis:
sections of a female in the appendix. H-E stain.
Observe the lateral alae [3oss (160X), 4oss (400X), 5oss (160X), 6oss
(400X)],
the typical eggs [7oss (160X), 8oss (250X), 9oss (400X)], the prominent
esophageal bulb (350 micron in diameter) [1oss (60X), 2oss (250X), 3oss
(160 X), 4oss (400X)], the cephalic space [10oss (160X)], and the cuticle [6oss (400X)]
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Courtesy of Laura
Davico Bonino MD, Laura Godio MD,
Istituto di Anatomia Patologica
Azienda Ospedaliera San Giovanni Battista di Torino
and Professor
Giuseppe Montrucchio MD Professore
di Medicina Interna, Università di Torino, U.O.A.D.U. Medicina V
Azienda Ospedaliera San Giovanni Battista di Torino. |
336Saygi-ic
Enterobius vermicularis:
a
cross section of a female in the appendix.
Observe the typical eggs, and the lateral alae (arrows).
(20 x H.E. stain)
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Images of the adult worm
329Saygi - 332Saygi
- 330Saygi - 331Saygi
- 336Saygi
Contribution of
Gulendame Saygi, M. Sc. Ph.D.:
Cumhuriyet Üniversitesi, Tip Fakültesi; Parazitoloji
Anabilim Dali, 58140,Sivas,Turkey.
The images are from the Parazitoloji
Atlasi, Sivas 2000.
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329Saygi-ic |
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Ent_f-ic
Enterobius vermicularis - female
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Ent_ f_2-ic
Enterobius vermicularis - female 2
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Enterobius vermicularis: anterior
end of a female.
Observe the swollen cuticle, the large oesophageal bulb,
and the extension of the uterus filled with eggs almost to the cephalic
region
(4 x, mounted in glycerine jelly)
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Enterobius vermicularis - female:
Courtesy of Dottoressa Vittoria
Fabbrizi e gruppo di
Batteriologia ospedale Civile di Teramo,
Italy. |
332Saygi-ic
Enterobius vermicularis: anterior
end of an adult
which was kept in 70% ethyl alcohol and 5% glycerine.
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330Saygi-ic |
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Ent_f_s-ic
Enterobius vermicularis female_scotch test |
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Enterobius vermicularis: vulvar
region of a female.
(4 x, mounted in glycerine jelly)
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Enterobius
vermicularis female_scotch test:
Courtesy of Dottoressa Vittoria
Fabbrizi e gruppo di
Batteriologia ospedale Civile di Teramo,
Italy. |
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331Saygi-ic |
Enterobius1-ic |
Enterobius vermicularis: posterior
end of a female.
Observe the eggs expelled by the worm in the field and the long,
pointed tail (hence the name of Pinworm).
(20 x, mounted in glycerine jelly)
Enterobius1: tail from a gravid
female filled with eggs (unstained).
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Enterobius1:
Courtesy of Dr. Marc Lontie:
Director of the laboratory of the
Medisch Centrum voor Huisartsen,
Maria Theresiastraat 63a; B-3000 Leuven, Belgium. |
oss5-ic
Enterobius vermicularis:
gravid female worm.
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oss3-ic |
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Ent_s-ic
Enterobius vermicularis scotch test 250X |
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Enterobius vermicularis: eggs are
rarely found in faeces;
they are more easily found in the perianal region.
Scotch-tape smear can be used to pick up the eggs and must
be made in the morning before defecation and bathing.
(Scotch-test)
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Enterobius
vermicularis scotch test 250X:
Courtesy of Dottoressa Vittoria
Fabbrizi e gruppo di
Batteriologia ospedale Civile di Teramo,
Italy. |
Enterobius vermicularis:
egg in human faeces
(wet mount preparation).
Enterobius2: Enterobius vermicularis:
asymetric egg in faeces with thin double shell, containg a folded larva.
Length: 55 µm (unstained).
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Enterobius2:
Courtesy of Dr. Marc Lontie:
Director of the laboratory of the
Medisch Centrum voor Huisartsen,
Maria Theresiastraat 63a; B-3000 Leuven, Belgium. |
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Enterobius
vermicularis embryonated egg 2-3-4 400X:
Courtesy of Dottoressa Vittoria
Fabbrizi e gruppo di
Batteriologia ospedale Civile di Teramo,
Italy. |
oss4-ic
Enterobius vermicularis: eggs are
thin shelled, ovoid and flattened on one side
and measure 50-60 by 20-30 µm; they often are embrionated.
oss6-ic
Enterobius vermicularis: scotch-tape smear showing an egg of
E.vermicularis and some eggs of Taenia spp.
oss7-ic
Enterobius vermicularis: unstained eggs.
Specimen collected from the skin of perianal area
using Graham‘s cellulose tape method.
Objective 40 X.
  
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