NEMATODES (ROUNDWORMS) Flashcards by MARY ANGELINE JACILDONE

Maria, a 5-year-old girl, presented to a local clinic complaining of diarrhea and gastrointestinal pain and bleeding.
Patient history revealed that Maria recently emigrated to the United States from Puerto Rico. The physician on duty ordered a series of stool samples for O&P. Barrel-shaped
structures, as noted below, that appeared to have plugs at each end were seen on the direct wet preps, concentrated wet preps after performing a zinc sulfate flotation method,
and permanent stains.

What is the scientific name and morphologic form of the parasite present in Maria’s samples?
What is the common name for this parasite?
How did Maria contract this parasite?
Which disease state is associated with this parasite?
Which morphologic form of this parasite may be visible
on microscopic examination of the intestinal mucosa of
this patient?

Trichuris trichiura egg.
Whipworm.
Ingestion of infective eggs.
Trichuriasis; whipworm infection.
Adult worms.

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The junvenile stage of developing nematode worms is referred to as?

Larvae

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Adult nematodes are never recovered in clinical
samples. True or False?

False

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Class of nematode that contains caudal chemoreceptors of round worms. The organ for the detection of food caudal chemoreceptors

Phasmid

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Species that parasitize the small intestine

“CASHTs”: Capillaria, Ascaris, Strongyloides, Hookworms, Trichenella spiralis

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Species that parasitize the large intestine

“ET”: Enterobius, Trichuris

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Species that parasitize the tissues

Wuchereria bancrofti, Brugia malayi, Loa Loa, Dracunculus medinensis

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Species that causes larva migrans in man

Ancylostoma braziliense, caninum and Toxocara

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Class of nematode that lacks phasmids or caudal chemoreceptors

Aphasmids

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Most primitive group of nematodes

Aphasmids

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Do aphasmids have a sensory bristles or papillae? True or False

False

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Common name of Trichinella spiralis?

Trichina Worm

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Trichinella spiralis
Infective stage?
Main Habitat?

Ova
a. Biopsies of these larvae often reveal a?
b. What is its notable features?

Adult Female
a. Notable features of a female adult T. spiralis?
b. Is the female adult viviparous?

Adult Male
a. Notable features of a male adult T. spiralis?

Laboratory Diagnosis
a. method of choice for recovery of the encysted larvae
b. Other laboratory findings may also serve as indicators for disease
c. In correlation to CC, what enzymes are elevated?
d. A test that uses antigen prepared from Trichinella larva
e. A test that uses albino rats

Life Cycle Notes
a. Human infection with T. spiralis is the result of accidental human infection with a parasite whose normal host is?
b. Human infection is a dead-end infection?

Disease: Trichinosis, Trichiniasis, Trichinelliasis
a. generalized inflammation of duodenal and jejunal mucose, malaise, nausea, diarrhea, and abdominal cramps
b. fever, facial edema (particularly the eyes), pain, swelling and weakness of the involved muscle
c. begins at about the end of the 3rd week; cyst wall subsides; the larva itself will calcify

-Encysted larva
-Small intestine, skeletal muscles (coiling up in the muscle fibers and becoming encysted)

Ova
-Distinctive inflammatory infiltrate
-coiled; Inflammatory infiltrate
present around nurse cell, spear-like burrowing tip at its tapering anterior end

Adult Female
-Blunt, round posterior end; single ovary with
vulva in anterior fifth of body
- Yes it is capable of laying live larvae

Adult Male
-single testis, curved posterior end with two rounded appendages

Laboratory Diagnosis
-Examination of the affected skeletal muscle/Muscle Biopsy
-eosinophilia and leukocytosis
-Elevated serum muscle enzyme levels, such as lactate dehydrogenase, aldolase, myokinase and creatinine phosphokinase aid in T. spiralis diagnosis.
-Bachmann Intradermal Test
-Beck’s Xenodiagnosis

Life Cycle Notes
- an animal (zoonosis)
-yes

Disease
-Intestinal invasion
- Muscle invasion
-Convalescence

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The specimen of choice for the identification of Trichinella spiralis is which of the following?
A. Cerebral spinal fluid
B. Stool
C. Skeletal muscle
D. Urine

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The diagnostic stage of Trichinella spiralis is which of the following?
A. Encysted larvae
B. Cysts
C. Eggs
D. Adult worms

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Trichinosis is acquired via which of the following?
A. Swimming in contaminated water
B. Consuming contaminated water
C. Ingestion of contaminated food
D. Inhalation of contaminated air droplets

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Common name of Capillaria philippinensis

Pudoc worm / mystery disease

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Capillaria philippinensis
Infective stage?
Intermediate Host?

Developmental Stage:
A. Ova
> resembles “________” appearance

B. Atypical female
> the ______ eggs in utero are arranged in the ________ (Oviparous)

C. Typical female
> the _____ eggs in utero are arranged in _____
(Larviparous); does it cause autoinfection?

D. Male
>characterized by the presence of?

Disease: Capillariasis or Mystery Disease
a. what is Borborygmus/ Borborygmi?

Laboratory Findings
a. Shows a?

Diagnosis
a. Diagnosis is based on finding characteristic
eggs in the feces by?

Drug of choice
a. The drug of choice for the treatment
of intestinal capillariasis is

-Encysted larva/3rd stage
-glassfish, “bagsit”, “bagsang”, “ipon”

Developmental Stage:
A. Ova
- pale yellow with moderately thick striated shell, and with flattened bipolar plugs; resembles “peanut-shaped” appearance

B. Atypical female
-8-10 eggs in utero; single row

C. Typical female
-40-45 eggs; 2-3 rows; autoinfection

D. Male
-a chitinized spicule and a long spicule sheath extending beyond the length of the worm

Disease
-Gurgling stomach; diarrhea with constipation

Laboratory findings
-protein-losing enteropathy and hypoalbuminemia; malabsorption of fats and
sugars; decreased excretion of xylose; low serum potassium, sodium and calcium; and high levels of immunoglobulin E.

Diagnosis
-by direct smear or wet mount, as well as by stool concentration methods.

Drug of choice
-Albendazole, Mebendazole

Epidemiology
-Tagudin Ilocos Sur, Thailand

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Drug of choice:
a. Protozoan?
b. Filarial?
c. Fowleri, acanthamoeba?
d. Nematode?

a. Mitronedazole
b. DEC
c.
d. Albendazole, Mebendazole

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Common name of Capillaria hepatica

Capillary liver worm

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Capillaria hepatica
Infective stage?
Main habitat?

Developmental Stages
a. Ova
- what are the shaped of its eggs?
-Outer shell

-Embryonated ova
-Liver of the host

Developmental Stages
a. Ova
- lemon shaped eggs
-Pitted like golf ball

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Common name of Trichuris trichuria

Whipworm

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Trichuris trichuria
Infective stage?
Main Habitat?

Ova
a. resembles a?
b. Shell Smooth; yellow-brown color because of?

Adult
a. The posterior end of the adult T. trichiura is large and resembles that of a?
b. It has a coiled posterior portion

Laboratory Diagnosis
a. Specimen of choice for the recovery of T.
trichiura eggs is?

Embryonated Ova
Cecum and appendix

Ova
-Barrel/football-shaped, Japanese lantern; A prominent hyaline polar plug is visible at each end.
-bile stained

Adult
-Whiplike (3/5 is attenuated)
-Male

Laboratory Diagnosis
-Stool

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Trichuris trichiura eggs are characterized by the presence of which of the following?
A. Triple-layer cell wall
B. Flattened side
C. Hyaline polar plugs
D. Prominent cytostome

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Of the following choices, the best laboratory diagnosis technique for the recovery of Trichuris trichiura eggs is which of the following? A. Zinc sulfate flotation B. Modified acid-fast stain C. Ethyl acetate concentration D. Wright-Giemsa stain

Children infected with Trichuris trichiura commonly suffer from: A. Mental confusion B. Hemoglobinuria C. Severe anemia D. Rectal prolapse

Common name of Ascaris lumbricoides

Giant intestinal roundworm

Most common intestinal roundworm

Asacaris lumbricoides

Ascaris lumbricoides Infective stage Main habitat Mechanical Vector Developmental Stages a. Ova -Unfertilized ova is? -Layer that is absent in old specimens -Fertilized ova is? -3 layers: i. outermost mamillated layer with a tanning action ii. chitinous layer; secretory product of the egg iii. fertilization membrane; protects the inner embryo b. Fertilized egg - A thick nitrogen-containing polysaccharide coating called? also known as a shell, is sandwiched in between the embryo and mammillated albuminous material (corticated) c. Adult - white, creamy, or pinkish yellow when freshly expelled and resembles? - head is provided with ______ lips which are finely denticulated -The adult female resembles a _______ in thickness. Diseases: Ascariasis, Dooryard or Backyard Infection -pneumonia like with infection of Ascaris lumbricoides

Embryonated Ova Lumen of the SI Cockroaches Developmental Stages a. Ova -long and narrower/oblong -Albuminoid layer -Broadly ovoidal and thick/Circle -i. Albuminous layer ii. Chorionic/true shell iii. Vitelline layer b. Fertilized egg - Chitin c. Adult -earthworm -with three conspicuous lips -pencil lead Diseases -Loeffler's syndrome

Ascaris lumbricoides Stool examination may give negative results due to the following: -Infection is still early (worms are still immature) -During larval migration through the bloodstream -Male worms are the only present in the intestine

keep in mind

Individuals contract Ascaris lumbricoides via which of the following? A. Inhalation B. Insect bite C. Ingestion D. Inappropriate sexual practices

The term that describes the lack of an outer mammillated albuminous coating is called which of the following? A. Unfertilized B. Fertilzed C. Corticated D. Decorticated

The specimen of choice for the recovery of Ascaris lumbricoides eggs is which of the following? A. Stool B. Gallbladder biopsy C. Urine D. Sputum

Kato thick or Kato Katz a. For screening purposes (Quali) b. for egg count (Quanti)

a. Kato thick b. Kato katz

Unholy trinity

HAT (Hookworms, Ascaris, Trichuris)

Human Hookworms Common Name of N. americanus Common name of A. duodenale A. ceylanicum

-American murderer/American hookworm/New World Hookworm -Old World Hookworm

Animal Hookworms Common name of A. braziliense Common name of A. caninum

- cat hookworm - dog hookworm

IDA (capable of depriving individual with Fe) is commonly associated with? Vit. B12/Pernicious Anemia is commonly associated with?

-Hookworms -D. latum (Cestodes)

Hookworm Ova -how many cell stage when passes in the feces (surrounded by a clear zone) -Sensitive for? Feeding stage (active metabolism)? -short and stout -has a long narrow buccal cavity -flask-shaped esophagus -very small genital primordium Non-feeding stage; infective stage? -mouth is closed with a protecting sheath -longer and slender with a pointed posterior end Buccal Cavity i. 1 pair of semilunar cutting plates ii. 2 pairs of fused ventral teeth iii. 3 pairs of ventral teeth iv. 1 pair of larger outer teeth and 1 pair of very inconspicuous median teeth Mode of Transmission? Diseases Due to larval stage: a. Intense itching, edema and erythema and later papulovesicular eruption b. Creeping eruption aka ? -“Serpiginous tunnel” in the stratum germinativum of the skin c. causes pulmonary lesions The primary means for laboratory diagnosis of hookworm is the recovery of the eggs?

-4-8 - sensitive for disintegration -RHABDITIFORM LARVA -FILARIFORM LARVA i. N. americanus ii. A. duodenale iii. A. caninum iv. A. brazilliense -MOT: skin penetration Diseases: a. Ground itch (aka Coolie itch or Dew itch) b. aka Cutaneous Larva Migrans/Plumber’s itch/Duck hunter’s itch - “Serpiginous tunnel” in the stratum germinativum of the skin c. Wakana disease -Stool samples

Blood loss: N. americanus A. duodenale

N. americanus: 0.03-0.05 ml/day A. duodenale: 0.16-0.34 ml/day

Medium used in Harada Mori culture technique -if nasa taas? -if nasa baba?

Distilled H2O -Strongy -Hookworm

This adult hookworm is characterized by a buccal cavity that contains teeth. A. Ancylostoma B. Necator C. Both Ancylostoma and Necator D. Neither Ancylostoma nor Necator

Individuals contract hookworm via which of the following? A. Contaminated water B. Skin penetration C. Insect bite D. Contaminated food

Which of the following are appropriate Ascaris lumbricoides prevention and control strategies? A. Proper water treatment B. Appropriate food handling C. Use of insect repellent D. Proper sanitation practices

Common name of Strongyloides stercoralis

Threadworm

Strongyloides stercoralis Habitat? Developmental stages: a. Ova resembles a? - not found in feces except? b. Adult has no teeth, no cutting plates but bears a? Diseases Laboratory Diagnosis -Stool concentration with _______ has successfully recovered these eggs Treatment -both an ovicidal & larvicidal

Upper small intestine (Duodenum) Developmental stages: a. chinese lantern - diarrhea and hyperistalsis b. crown of chitinous, leaf-like processes Disease: Cochin-china diarrhea Laboratory Diagnosis: -Zinc sulfate Treatment -Thiabendazole

This diagnostic stage of Strongyloides stercoralis is best seen in stool using fecal concentration techniques: A. Eggs B. Rhabditiform larvae C. Filariform larvae D. Adult worms

The life cycle of Stronglyoides most resembles that of which of the following? A. Pinworm B. Whipworm C. Hookworm D. Threadworm E. Human roundworm

The two clinical symptoms most commonly associated with Trichinella spiralis are which of the following? A. Constipation and abdominal pain B. Vomiting urticaria C. Diarrhea and vomiting D. Abdominal pain and diarrhea

Enterobius vermicularis * Ova: a. Developing larva surrounded by * Adult: - Expansion of cuticle called the "________ alae or _________ wings" - It has an oral end and ___ lips - What is the shaped of the esophagus? a. Female - Tail is _____ resembles _________ * Specimen of choice: _________

* flattened on one side (D-shaped) a. conspicuous double-layered, thick-walled colorless shell *Adult - Cephalic alae/ lateral wings - oral end, 3 lips - Hour glass shaped esophagus a. Adult Female: Tail is pointed resembles pin head * Specimen of choice: Cellophane tape preparation

Common name of Enterobius vermicularis

Pin/Seat/Society Worm

True or False: It is believed that E. vermicularis may be responsible for the transmission of Dientamoeba fragilis

True :)

The most likely individual to contract pinworm infection is(are) a(an): A. Older adult B. Child C. Adult prisoner D. Military personnel

The morphologic forms recovered in cases of pinworm infection are which of the following? A. Eggs and adult females B. Adult males and females C. Eggs and larvae D. Larvae and adult males

Enterobius vermicularis: a. Main Habitat b. Infective Stage: c. Synonym name d. Nocturnal or diurnal perianal itching? e. Give 3 diagnosis for E. vermicularis

a. Cecum & Appendix b. Embryonated Ova c. Oxyuris vermicularis d. Nocturnal 10pm - 2am e. Graham scotch tape, NIH Swab technique, Schuffner & Swelling Rebel Method

Enterobius vermicularis is the most contaminant found in urine

TRUE

This species causes Visceral Larva Migrans

Toxocara species

Toxocara Species: a. Infective Stage b. Synonym names: c. Host d. Are Humans the accidental host? e. Paratenic Host f. Known as Dog Ascarid g. Known as Cat Ascarid h. Habitat

a. Embryonated ova b. Ascaris mystax, Belascaris mystax, Belascaris cati c. Dogs and Cats d. Yes e. Ducks & Rabbits f. Toxocara cani g. Toxocara cati h. Small Intestine

What are the 2 major forms of Toxocara species?

Ocular Larva Migrans (OLM) Visceral Larva Migrans (VLM)

Can Ocular Larva Migrans causes Blindness?

Yes

Toxocara egg: a. Color b. Spherical to slightly _______ shaped, thick shelled and has a _________ surface c. Is T. cati is slightly larger than T.canis?

a. Gold b. Pear shaped; pitted surface c. No. T. canis is slightly larger than T. cati

TRUE OR FALSE: I. The larvae of Toxocara species do not develop into the adults in human, a stool examination would not detect any Toxocara eggs II. Presumptive diagnosis of Toxocara is OLM and VLM

I. True II. True

Mimics the eggs of Hookworms

Trichostrongylus Species

Are Trichostrongylus Species considered as zoonotic infection? And are they herbivores?

Yes

Enumerate the human infections of Trichostrongylus Species

T. colubriforms T. orientalis T. axei T. brevi

Trichostrongylus Species: a. T. tenuis - infects b. T. axei - also known as c. T. colubriforms - also known as d. TRUE/ FALSE: - These are the less frequent Trichostrongylus species (T. probolurus, T. vitrinu)

a. poultry b. Stomach hairworm c. Bankrupt worms d. True

TRUE OR FALSE: The eggs of Trichostrongylus species are similar to Hookworm eggs

TRUE

Common name of Angiostrongylus cantonensis

Rat Lungworm / Rodent lungworm

Angiostrongylus cantonensis: a. Synonym b. Definitive Host - What is the IH? c. Main Habitat d. Infective Stage: e. Its diagnosis has a moderate to high eosinophlic count in the spinal fluid

a. Pulmonema cantonensis b. Rats - IH: Achatina fulica c. Lungs d. 3rd stage larva e. Brain dyscrasia

Angiostrongylus cantonensis Ova 1st or 3rd stage larva a. Distinct dorsal minute notch b. 2 well developed chitinous rods with expanded knob like tips

a. 1st b. 3rd

Angiostrongylus cantonensis: Adult Worms a. Female is described to have a transparent cuticle as _________ pattern b. Male has a well developed caudal bursa which is ________ shaped and single lobed

a. barber's pole b. kidney shaped

The transmission of Angiostrongylus cantonensis is through the ingestion of raw mollusks

TRUE

It is the common gastrointestinal parasite of marine mammals with Pseudoterranova

Anisakis Species

This causes Herring Disease

Anisakis Spp

Anisakis species: a. Infective Stage b. Enumerate the Anisakis simplex complex c. Enumerate the Pseudoterranova decipiens complex e. Treatment

a. 3rd stage larva b. A simplex sensu stricto, A pegreffii, A. berlandi c. P. decipiens sensu stricto, P. azarasi, P. cattani d. ALBENDAZOLE

Common name of Dracunculus medinensis

Guinea worm Fiery serpent of the Israelites Medina worm Serpent worm Dragon worm

Dracunculus medinensis: a. Enumerate the disease caused by this parasite b. Habitat c. Life Span: d. Infective Stage: e. Diagnostic Stage f. Treatment

a. Dracunculiasis/Dracontiasis/ Dracunculosis b. Cutaneous & Subcutaneous c. 12-18 months d. 3rd Larval stage e. Rhabditiform larva f. Mebendazole, Niridazole, Thiabendazole

The diagnosis of calcified worm found in Dracunculus medinensis is by

Xray

The two morphologic stages present in the Dracunculus medinensis are which of the following? A. Eggs and larvae B. Larvae and adults C. Eggs and adults D. None of the above

The specimen of choice for the recovery of Dracunculus medinensis is which of the following? A. Infected ulcer B. Skeletal muscle C. Stool D. Blood

When humans contract Dracunculus medinensis, the parasite’s life cycle ceases to continue A. True B. False C. Unable to determine

Common Names: 1. Trichinella spiralis 2. Trichuris trichiura 3. Enterobius vermicularis 4. Dracunculus medinensis 5. Necator americanus

1. Trichina worm 2. Whipworm 3. Pinworm 4. Guinea worm 5. Hookworm

The eggs of which group of nematodes are indistinguishable? A. Whipworm and trichina worm B. Hookworm and threadworm C. Guinea worm and roundworm of man D. Pinworm and whipworm

Once inside a human, these two nematodes take up residence outside the intestinal tract. A. Enterobius vermicularis and Strongyloides stercoralis B. Necator americanus and Ancylostoma duodenale C. Dracunculus medinensis and Trichinella spiralis D. Trichuris trichiura and Ascaris lumbricoides

Common Diseases 1. Roundworm of man 2. Whipworm 3. Hookworm 4. Pinworm 5. Guinea worm

1. Ascariasis 2. Trichuriasis 3. Ancylostomiasis 4. Enterobiasis 5. Dracunculosis

These two nematodes are similar in that they are both suspected of being transport hosts of Dientamoeba fragilis. A. Trichinella and Dracunculus B. Necator and Trichuris C. Strongyloides and Ancylostoma D. Ascaris and Enterobius

The eggs of these two nematodes are never to rarely seen in stool samples. A. Trichina and threadworm B. Whipworm and roundworm of man C. Guinea worm and pinworm D. Threadworm roundworm and hookworm

Egg Morphology 1. Flattened on one side 2. Obvious albuminous coating 3. Surrounded by a nurse cell 4. Thin shell surrounding embryonic cleavage 5. Polar plug on each end

1. E. vermicularis 2. A. lumbricoides 3. T. spiralis 4. Ancylostoma 5.Trichuris trichuria

Which of these parasites are contracted via skin penetration? A. Enterobius, Necator, Dracunculus B. Ascaris, Trichinella, Ancylostoma C. Trichuris, Strongyloides, Enterobius D. Ancylostoma, Strongyloides, Necator

NEMATODES (ROUNDWORMS) Flashcards

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