METAZOANS (Roundworms or Nematodes) Flashcards
memorization
Class Adenophoerea (Aphasmids) roundworm species:
- Trichuris trichiura
- Capillaria philippinensis
- Capillaria hepatica
- Trichinella spiralis
Other name of T. trichiura:
“Whipworm”
Other name of C. philippinensis:
“Pudoc worm”
Other name of Capillaria hepatica:
“Capillary liver worm”
Other name of Trichinella spiralis:
“Trichina spiralis”
Ova = Lemon-shaped, barrel-shaped, Japanese lantern; with bipolar hyaline plugs:
T. trichiura ova
Ova = Peanut-shaped/ guitar-shaped, with flattened bipolar plugs:
Capillaria philippinensis
Ova = Lemon-shaped; outer shell; pitted like a golf ball appearance
Capillaria hepatica
Ova/egg: none
Larva: spear-like tip
Trichinella spiralis
Trichiuris trichiura
IS:
DS:
IH:
Habitat:
Trichiuris trichiura
IS: Embryonated egg
DS: Unembryonated egg
IH: None
Habitat: LARGE INTESTINE
Capillaria philippinensis
IS:
DS:
IH:
Capillaria philippinensis
IS: Larva in fish
DS: Unembryonated egg
IH: Fish
Capillaria hepatica
IS:
DS:
Capillaria hepatica
IS: Embryonated egg
DS: Egg in liver biopsy
Trichinella spiralis
IS:
DS:
IH:
Trichinella spiralis
IS: Encysted larva
DS: Encysted larva (in muscles)
IH: Pig
Diagnostic prodecure for C. hepatica:
Liver biopsy
Diagnostic procedure for T. spiralis:
- Muscle biopsy
- Beck’s xenodiagnoses - using albino rats
- Bachman intradermal test
How does C. philippinensis cause autoinfection
Because of the larviparous nature of C. philippinensis; internal autoinfection
Giant intestinal round worm; Largest intestinal nematode;
Ascaris lumbricoides
Enterobius vermicularis is also known as:
“pinworm”, “seatworm”
Old name: Oxyuris vermicularis
Egg stage of A. lumbricoides; Golden brown, thick shelled. 3 layers:
Fertilized ova
Egg stage of A. lumbricoides; longer and narrower, no glycogen membrane
Unfertilized ova
Shape of E. vermicularis ova:
D-shaped
Ascaris lumbricoides
IS:
DS:
Habitat:
Ascaris lumbricoides
IS: Embryonated egg
DS: Unembryonated egg
Habitat: Small intestine
note: Heart-to-Lung migration
Enterobius vermicularis
IS:
DS:
Enterobius vermicularis
IS: Mature/ Embryonated egg
DS: Mature/ Embryonated egg
Note: can cause AUTOINFECTION
Diagnosis for E. vermicularis:
Perianal swab (Graham’s scotch tape method)
Graham’s scotch tape method is best done:
Early in the morning before the patient bathes or defecating
Toxocara canis/ Toxocara cati
IS:
DS:
Toxocara canis/ Toxocara cati
IS: Embryonated egg
DS: Larva (affected tissue)
Toxocara canis/ Toxocara cati causes:
- Visceral larva migrans - Infection of visceral organs
- Ocular larva migrans - eye infection
Dioctophyma renale is also known as:
“Giant kidney worm”
Necator americanus is also known as:
New world hookworm
Ancylostoma duodenale is also known as:
Old world hookworm
Other name
Ancylostoma caninum:
Ancylostoma braziliense:
Ancylostoma caninum: Dog hookworm
Ancylostoma braziliense: Cat hookworm
Identify:
Buccal capsule: 1 pair of semilunar cutting plates
Copulatory bursa: Longer than broad
Dorsal rays - deep cleft and tips bipartite
2 spicules - Fused and barbed
Necator americanus
Identify:
Buccal capsule: 2 ventral pairs of FUSED teeth
Copulatory bursa: Short and broad
Dorsal rays - shallow cleft and tips tripartite
2 spicules - unfused and NOT barbed
Ancylostoma duodenale
Identify:
Buccal capsule: 3 ventral pairs of fused teeth
Copulatory bursa: Large, flame-shaped
Rays - long and slender
Ancylostoma caninum
Identify:
Buccal capsule: 2 ventral pairs of UNFUSED teeth
Copulatory bursa: As broad as long
Rays - stunted
Ancylostoma braziliense
N. americanus/ A. duodenale
IS:
DS:
Habitat:
N. americanus/ A. duodenale
IS: Filariform larvae
DS: Unembryonated egg in stool
Habitat: Small intestine
**Heart-to-Lung migration
A. caninum/ A. braziliense IS and DS:
Ectoparasite (skin only)
MOT of N. americanus & A. duodenale:
Skin penetration
A. duodenale: Skin penetration & ingestion of larva
Hookworm spp that causes Wakana syndrome due to ingestion of larva
Ancylostoma duodenale
Diseases caused by N. americanus:
Larval penitration:
- dermatitis lesion (ground itch, dew itch, coolie itch)
Larval migration: pneumonitis + eosinophilia (Loeffler’s syndrome)
Heavy infection:
- ANEMIA (microcytic hypochromic)
- Hypoalbuminemia
Disease caused by A. duodenale:
Same as N. americanus
** “wakana’s syndrome” - due to ingestion of larva, nausea, vomiting, pharyngeal irritation, cough, dyspnea
Diagnostic procedure for HOOKWORMS:
- Direct microscopy (DFS, KATO)
- Kato-Katz method (egg-counting method)
- Coproculture —> Baermann technique
- Harada-Mori technique (test-tube culture method)
Also known “Threadworm”
Strongyloides stercoralis
True or False
threadworm can exist as both a free-living organism or a parasite thriving inside a host.
Free-living existence: both male and female present
Parasitic existence: only male adult
False
In parasitic existence, ONLY FEMALE ADULGT is present
Can Strongyloides stercoralis undergo heart-to-lung migration?
YES
part of ASH mnemonic, heart-to-lung migration
-Ascaris
-Strongyloides
-Hookworm
Strongyloides stercoralis
IS:
DS:
Strongyloides stercoralis
IS: Filariform larva
DS: Rhabditiform larva (stool)
MOT of S. stercoralis:
Skin penetration of filariform larva
In Harada-mori, Strongyloides stercoralis:
Moves UPWARDS instead of downwards like most filariform larva
Difference of rhabditiform larvae of Hookworm and S. stercoralis:
Rhabditiform larvae
Hookworm:
- LONG BUCCAL CAVITY
- SMALL genital primordium
Strongyloides:
- SHORT BUCCAL CAVITY
- PROMINENT/LARGE genital primordium
Difference of filariform larvae of Hookworm and S. stercoralis:
Filariform larvae
Hookworm:
- SHORT ESOPHAGUS
- POINTED TAIL
Strongloides;
- LONG ESOPHAGUS
- NOTCHED TAIL
Vector of Wuchereria bancrofti:
Mosquito (Anopheles, Culex, Aedes)
Vector of Brugia malayi:
Mosquito (Mansonia)
Also known as African eye worm:
Loa loa
Which Filaria causes Upper Elephantiasis with chylocoele/hydrocoele & chyluria
Wuchereria bancrofti
Which Filaria causes Lower Elephantiasis without chyluria
Brugia malayi
Which Filaria causes blinding filariasis, river blindness
Onchocerca volvulus
Vector of Onchocerca volvulus
Black fly/ Buffalo knot
Vector of Loa loa
Mango/ Deer/ Tabanid fly (Chrysops)
Vector of Mansonella spp:
Biting midges (Culicoides)
Filaria that causes Ugandan Eye Worm, Calabar-like swelling, Kampala:
Mansonella perstans
Filaria that inhabits the lymnphatics:
- Wuchereria bancrofti
- Brugia malayi
Filaria that inhabits the subcutaneous tissue:
- Loa loa
- Onchocerca volvulus
Filariae Tail free of nuclei (without nuclei):
- Wuchereria bancrofti
- Onchocerca volvulus
- Mansonella ozzardi
Filariae tail with nuclei:
- Brugiya malayi
- Loa loa
- Mansonella perstans
- Mansonella streptocerca
Filariae tail that is sheathed:
- Wuchereria bancrofti
- Brugia malayi
- Loa loa
Filaria tail that is sheathed and free from nuclei
Wuchereria bancrofti
Filaria tail that is sheathed and has two (2) nucleus at tip of tail
Brugia malayi
Filaria tail that is sheathed and continuous row of posterior nuclei
Loa loa
Filaria tail that is unsheathed and free of nuclei
- Onchocerca volvulus
- Mansonella ozzardi
Filaria tail that is unsheathed and nuclei in tip of tail
Mansonella perstans
Filaria tail that is unsheathed and nuclei extends to tip
Mansonella streptocerca
Filaria that requires skin nips for diagnosis:
- Onchocerca volvulus
- Mansonella streptocerca
Filaria that requires Blood specimen for diagnosis:
- Wuchereria bancrofti
- Brugia malayi
- Loa loa
- Mansonella perstans
- Mansonella ozzardi
FIlaria that requires blood, csf, urine and sputum for diagnosis:
Loa loa
Filaria that requires the method Mazzoti test:
- Onchocerca volvulus
- Mansonella streptocerca
**The filariae that requires skin nips for diagnosis
To collect blood even at day time for the diagnosis of nocturnal filaria (W. bancrofti & B. malayi), use:
Diethylcarbamazine (DEC)
Also known as the “Guinea worm”, “Serpent worm”, “Dragon worm”, “Medina worm”, “Fiery Serpent of Israelites”
Dracunculus medinensis
Dracunculus medinensis
IS:
DS:
MOT:
IH:
Dracunculus medinensis
IS: Larva
DS: Worm, Larva
MOT: Ingestion of contaminated water
IH: Cyclops (copepods, “water fleas”)
Also known as “Rat lung worm”
Angiostrongylus cantonensis
The uterine tubules of female worm (A. cantonensis) has “__________” appearance
“Barber’s pole appearance”
Also known as “Herring’s worm”
Anisakis
Also known as “Dog heartworm”
Dirofilaria immitis