NEMATODES (ROUNDWORMS) Flashcards
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.
The junvenile stage of developing nematode worms is referred to as?
Larvae
Adult nematodes are never recovered in clinical
samples. True or False?
False
Class of nematode that contains caudal chemoreceptors of round worms. The organ for the detection of food caudal chemoreceptors
Phasmid
Species that parasitize the small intestine
“CASHTs”: Capillaria, Ascaris, Strongyloides, Hookworms, Trichenella spiralis
Species that parasitize the large intestine
“ET”: Enterobius, Trichuris
Species that parasitize the tissues
Wuchereria bancrofti, Brugia malayi, Loa Loa, Dracunculus medinensis
Species that causes larva migrans in man
Ancylostoma braziliense, caninum and Toxocara
Class of nematode that lacks phasmids or caudal chemoreceptors
Aphasmids
Most primitive group of nematodes
Aphasmids
Do aphasmids have a sensory bristles or papillae? True or False
False
Common name of Trichinella spiralis?
Trichina Worm
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
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
C
The diagnostic stage of Trichinella spiralis is which of the following?
A. Encysted larvae
B. Cysts
C. Eggs
D. Adult worms
A
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
C
Common name of Capillaria philippinensis
Pudoc worm / mystery disease
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
Drug of choice:
a. Protozoan?
b. Filarial?
c. Fowleri, acanthamoeba?
d. Nematode?
a. Mitronedazole
b. DEC
c.
d. Albendazole, Mebendazole
Common name of Capillaria hepatica
Capillary liver worm
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
Common name of Trichuris trichuria
Whipworm
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
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
C
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
A
Children infected with Trichuris trichiura commonly suffer from:
A. Mental confusion
B. Hemoglobinuria
C. Severe anemia
D. Rectal prolapse
D
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
C
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
D
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
A
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)