nematodes Flashcards
Enterobius vermicularis:
1. drug of choice primary and secondary
2. disease
3. diagnostic technique and its advantages
4. what does the ova and adult worm male and female look like
5. where can you find eggs and worm
6. parts of pinworm (5)
- primary = mebendazole, albendazole
secondary = Pyrantel pamoate - Enterobiasis
- Graham’s Scotch adhesive tape swab =
highest % of positive result
low cost
easy to perform
sensitive and specific
result: any pinworm/ eggs on skin will stick to the tape, press sticky side of tape to slide then –> microscope - ova = assymetrical, one side flattened , translucent shell –> triple albuminous covering and inner embryonic lipoidal membrane
adult worms= cephalic expansion = anterioir end (taas)
posterior esophageal bulb = posterior (baba)
male = curl end , with 1 spicule
female = long pointed tail
- adult worm = feces/ perianal fold
eggs= feces 5% only - cephalic alae, muscular portion, isthmus, bulbous portion, intestine
enterobius:
1. infective and diagnostic stage
2. transmission
3. DH, IH, Vector
4. prevention and control
- infective= ingested embryonated eggs
diagnostic = eggs on perianal folds and adult worms - ingestion and inhalation of embryonated eggs
- humans = only host
vector = none - hygiene, shower not bathtub, underwear/sheets/etc. washed in hot soapy water, chemotherapy for entire family
enterobius AKA and life cycle
Enterobius vermicularis = human pinworm
cure of enterbous considered after :
how many perianal smears on consecutive days
using what method = found to be negative
7 Perianal smears
scotch tape swab method
autoinfection meaning and can be seen in (4)
mean: infected person is source of infection [CHEST]
Capillaria philippinensis,
Enterobius vermicularis, Hymenolepis nana, and
Strongyloides stercoralis,
taenia solium
nematodes usually seen in intestine (4) , colon (2) and lymph/ lymph vessel (2)
intestine = Ascaris, hookworms, Strongyloides, and Capillaria
colon= trichuris and enterobius
lymph / extraintestinal = Wuchereria and Brugia
nematode transmission :
ingestion of embryonated eggs (3)
skin penetration by filariform larvae (2)
bite of mosquito (2)
ingestion of infective larvae and what animal (3)
autoinfection (3)
tranmission through inhalation of embryonated eggs (2)
- ingestion of embryonated eggs = Ascaris, Trichuris , and Enterobius [ATE]
. - skin penetration by filariform larvae = hookworms and Strongyloides [HS]
- bite of mosquito vectors = Wuchereria and
Brugia [WB] - Ingestion of infective larvae = Capillaria from fish,
Trichinellafrom pork, and Parastrongylus from
snails. [CTP] - Autoinfection = Capillaria ,
Enterobius and Strongyloides [CES] - inhalation of embryonated eggs = Enterobius and Ascaris [AE]
Toxocara canis / cati :
1. drug of choice for the 3 types of disease
2. disease
3. diagnostic technique and its advantages (6)
4. what does the ova and larva look like
5. where can you find eggs and worm
6. parts of worm
canis = dog
cati = cat
- visceral toxocariasis = antiparasitic (albendazole / mebendazole) + anti-inflammatory medications
neurological or lung or cardiac = antihelmintic is mandatory = to kill parasite in brain
ocular = diff. measures to prevent damage to eye - toxocariasis
- fecalysis = not for human toxocariasis since eggs are not excreted or produced
- detection of larvae from biopsy tissues = definitive diagnosis , time consuming and difficult
- clinical and serologic test = commerical immunoglobulin (IgG) ELISA kits –> toxocara excretory-secretory (TES) antigens = detect igg antibodies against larvae
- western blot = more specific, cannot identify new and old infections
- PCR = good identification of species
- medical imaging technique = detect and localize granulomatous lesions due to toxocara larvae –> Computed Tomography (CT) and magnetic resonance imaging (MRI)
- ova = golden, spherical/pear-shaped, thick shell
t canis slightly larger than cani
larva = females are longer
Toxocara canis / cati :
1. infective and diagnostic stage
2. transmission
3. paratenic (carrier) and definitive host and accidental
4. prevention and control
- infective = ingesting infective eggs or undercooked meat of paratenic host / foodborne
diagnostic = l3 larvae in tissue, eggs in feces - vertical transmission (ex. puppies drink from mammary glands) , foodborne
- paratenic = humans / mammals and birds , defintive = canis= canids family/ dogs, cati = felids family/ cats
accidental = humans - antihelmintic treatment for dogs and cat, dogs cats treated every 6 months , cleaning up feces from soil and pavements , avoid eating raw meat , no hand to mouth activity
t or f: toxocara canis larvae passed in tissue and not detected morphoolgically
true
Capillaria Philippinensis :
1. drug of choice for the 3 types of disease
2. disease
3. diagnostic technique and its advantages (6)
4. what does the ova and larva look like
5. where can you find eggs and worm
6. parts of worm
c. philippinensis infect what animal
fish eating birds
C. philippensis:
1. infective and diagnostic stage
2. transmission
3. definitive host and intermediate
4. prevention and control
- infective = infective larvae, diagnostic = unembryonated eggs
- ingestion of undercooked fish
- definitive = humans , intermediate = species of freshwater fish
- cook fish well
c. philippinensis life cycle
unembryonated egg –> embryonate in external environemnt for 5-10 days soil or water –> ingestion of freshwater fish –> eggs hatch in fish intestine–> –> tissue –> ingestion of uncooked meat (larvae escape fish intestine and develop in adult worm in human intestine)
larvae can also reinvade intestine –> autoinfection –> hyerinfection (massive no. of adult worms)
larvae –> also can have eggs with no shell –> uterus of female and intestine
toxocara life cycle
unembryonated egg in feces –> embryonate in 1-4 weeks –> infective egg with L3 larvae –> ingestion of egg by humans –> hatch in the gut wall –> tissue
