Lecture: Intestinal Nematodes Flashcards
Largest and most common nematode
Ascaris lumbricoides
Measure of male Ascaris
15 – 30 cm by 3 mm
Measure of female Ascaris
20-45 cm by 5 mm
Terminal mouth of Ascaris has _
Trilobate lips
Measure of fertilized Ascaris ova
45-75 microns by 35-45 microns
Measure of unfertilized Ascaris ova
88-94 microns
What layer is absent in unfertilized Ascaris ova?
Vitelline layer
Ascaris ova without mammillary coat are called _
Decorticated
Ascaris ova with mammillary coat are called _
Corticated
Fertilized ova needs embryonation in _
Soil
A female Ascaris worm has a productive daily output of
200,000
Ovipositing female develop in about _ after infection and they live from _
2 to 2 ½ months
12 to 18 months
Ascaris of pig
Ascaris suum
Piperazine and Pyrantel pamoate are used these days because these drugs have a _ on the parasite causing paralysis.
Neuromuscular blocking effect
Stool examination may give a negative Ascaris finding in the following conditions:
a. when the patient is actually free from Ascaris infection
b. worms are still immature in the lumen
c. during larval migration
d. when only male worms are present in the intestine
Measure of adult Toxocara female worm
10-12 cm
Examination of stool from infected patients of Toxocara is not useful. Why?
Because egg-laying adults are not present.
Measure of Trichuris female
3.5 to 5 cm
Measure of Trichuris male
3 to 4.5 cm
Measure of Trichuris ova
50-54 by 22-23 microns
Distinguishing feature of Trichuris ova
Barrel shaped/lemon shaped/football shaped or Japanese lantern in appearance with prominent bipolar plugs on both ends
The development period from the ingestion of Trichuris eggs to ovipositing adult worms covers about
30-90 days
The number of eggs produced per day by a Trichuris female has been establishing at
3,000 to 10,000
Life span of Trichuris
4-6 years
The prevalence rate of Trichuriasis in the Philippines
ranges from _
80-90%
The large buccal capsule of A. duodenale is equipped with _
Two pairs of ventral teeth
The male A. duodenale worms have a fan-like organelle at the posterior portion known as _
Copulatory bursa or bursa copulatrix
The copulatory bursa of A. duodenale has a _ or _ dorsal ray
Tridigitate or Tripartite
The buccal capsule of N. americanus is provided with a _
Pair of semi-lunar cutting plates
The bursa copulatrix of N. americanus is longer than broad with a _ or _ dorsal ray
Bipartite or bidigitate
Feeding stage of Hookworm
L1 or Rhabditiform
Non-feeding stage or infective stage of Hookworm
L3 or Filariform
Measure of Hookworm eggs
56-60 by 34-40 microns
The life span of the Hookworms is from
2-13 years
Ancylostoma duodenale female produces _ daily
30,000 eggs
Necator americanus female produces _ daily
9,000 eggs
Percutaneous entry of the infective filariform larvae is often characterized by an itching sensation or dermatitis known as
Ground itch or dew itch
A syndrome caused by the massive pulmonary migration of larval stages
of hookworms
Pulmonary lesion or Wakana disease
A dermatitis characterized by serpiginous intracutaneous lesions caused by migration of the filariform larvae or nematode larvae that normally do not infect the human host like A. caninum and A. braziliense
Creeping eruption or Cutaneous larval migrans
Low level of albumin due to combined loss of blood, lymph and protein via sucking of Hookworms
Hypoalbuminemia
In the Philippines, the overall prevalence rate of hookworm infection is about _ wherein the
dominant specie is _
5-45%
N. americanus
Strongyloides of monkeys and primates
S. fuelleborni
Measure of parasitic S. stercoralis female
2–7 mm in length
30–4 um in width
Measure of E. vermicularis male
2-5mm in length
Measure of E. vermicularis female
8-13mm in length
A pair of lateral cuticular wing-like expansion at the anterior of E. vermicularis end known as _
Cephalic alae
Measure of E. vermicularis eggs
50–60 by 20–30 microns
The eggs are fully embryonated when laid and will mature within _ after oviposition of gravid female
6 hours
A gravid female may oviposit _ eggs per day
4,672 to 16,888
In the Philippines, it is _ among school children from exclusive private schools and _ from those coming from public schools are found with E. vermicularis infection.
29%
56%
Measure of C. philippinensis male
2.13 to 3.17 mm in length
Measure of C. philippinensis female
2.5 to 4.3 mm in length
Two Types of Capillaria female
Typical
Atypical
The first case of human infection with Capillaria philippinensis occurred in _ from _
1963
Ilocos Norte
