(M) Nematoda: Secernentea: Ascaradida (lecture-based) Flashcards
A. lumbricoides (lesson 1), T. canis, T. cati, Anisakis spp. (lesson 2)
Order of subclass
Enumerate all under this subclass: secernentea (5)
- Ascaradida
- Strongylida
- Rhabditida
- Oxyurida
- Spiruruda
Superfamily of the order Ascaradida
Ascaridoidea
Species of the super family Ascaridoidea
- Ascaris lumbricoides
- Toxocara canis
- Toxocara cati
- Anisakis spp.
- It has a worldwide distribution, (WHO Classification of Helminthes), and is soil transmitted.
- Incidence of infection among children is greater than adult individuals.
- Most common helminth infection of man
A. lumbricoides
ASCARIS LUMBRICOIDES AKA
Giant intestinal roundworm
LIFE CYCLE: ASCARIS LUMBRICOIDES
MOT
ingestion of viable, embryonated eggs present in foods and/or drinks
LIFE CYCLE: ASCARIS LUMBRICOIDES
Give the excystation after the egg hatches the small intestine
ano nangyare after
larva penetrates the intestinal wall, enters
venous circulation, passes through the liver, and enter the right side of the heart.
intestinal wall -> circulation -> liver -> right side of the heart
LIFE CYCLE: ASCARIS LUMBRICOIDES
It is carried by blood to the lungs and develops into the?
anong stage
4th larval stage
blood-lung phase cycle.
LIFE CYCLE: ASCARIS LUMBRICOIDES
The larva breaks through pulmonary capillaries, goes into the air sacs, to the bronchioles, bronchi, trachea, epiglottis, and then?
swallowed
LIFE CYCLE: ASCARIS LUMBRICOIDES
Where does the larva in the stomach goes to? to become adult worms
small intestine (final habitat)
mainly lumen of the ileum
Mating takes place and females lay eggs, which are discharged into the feces of human host
PATHOLOGY: ASCARIS LUMBRICOIDES
pathogenic to man
larva and adults
PATHOLOGY: ASCARIS LUMBRICOIDES
- where the passage of larvae through liver & lungs provokes no remarkable pathologic symptoms unless the number of larvae is immense.
- Eosinophilic infiltration & granuloma formation around the path of migrating larvae
- Fibrosis of the periportal & interlobular spaces
larval migration
PATHOLOGY: ASCARIS LUMBRICOIDES
o Migratory larvae in the lungs cause tiny
hemorrhages in the alveoli, which incite cellular
infiltration and consolidation.
o Fever, cough, eosinophilia, dyspnea, and rales may
be present.
Ascaris pneumonitis
PATHOLOGY: ASCARIS LUMBRICOIDES
- Severe pulmonary symptoms
- Dyspnea, dry productive cough
- X-ray: scattered, shifting mottled lung infiltration
- Spontaneously clearing associated w/ marked peripheral eosinophilia: Loffler’s syndrome
reffered to as
LOEFFLER’S PNEUMONITIS
PATHOLOGY: ASCARIS LUMBRICOIDES
Adult worms in the small intestine, mainly in the
ileum tend to be well tolerated unless infection is
heavy and/or the patient’s nutrient intake is
inadequate.
INTESTINAL ASCARIASIS
PATHOLOGY: ASCARIS LUMBRICOIDES
Children may have intermittent colicky abdominal
cramps, loss of appetite, and protruding abdomen (pot-belly appearance).
INTESTINAL ASCARIASIS
PATHOLOGY: ASCARIS LUMBRICOIDES
TOF. Single worm can cause serious disease
T
PATHOLOGY: ASCARIS LUMBRICOIDES
Worms may be entangled to each other resulting to a?
ball of worms or Ascaris bolus
PATHOLOGY: ASCARIS LUMBRICOIDES
Ascaris bolus may lead to?
intestinal obstruction
PATHOLOGY: ASCARIS LUMBRICOIDES
The worm is also able to perforate intestinal wall that
will result to
peritonitis
PATHOLOGY: ASCARIS LUMBRICOIDES
The worm in the peritoneum can enter the liver to produce
Ascaris liver abscess
PATHOLOGY: ASCARIS LUMBRICOIDES
TOF. Allergic manifestations may appear such as asthma-like symptoms and urticaria
T
o Bronchospasm & pulmonary infiltrates
o Pronounced during pulmonary migration
o Asthma & urticaria may continue during intestinal
phase
PATHOLOGY: ASCARIS LUMBRICOIDES
Heavy worm burden may cause
protein-calorie malnutrition or impairment of growth
PATHOLOGY: ASCARIS LUMBRICOIDES
Worms that become erratic or restless cause them to enter structures resulting to?
familiarize mo nalang
appendicitis, biliary duct, to cause biliary obstruction, or pancreatic duct, causing acute pancreatitis.
PATHOLOGY: ASCARIS LUMBRICOIDES
Erratic worms may go to the epiglottis to cause edema
that may lead to airway obstruction and therefore?
asphyxia
DIAGNOSIS: A. LUMBRICOIDES
ENUMARATE
- Sputum
- gastric washings
- DFS
- Abdominal X-ray
- Barium Swallow
DIAGNOSIS: A. LUMBRICOIDES
o To confirm Ascaris Loeffler’s pneumonitis
o Demonstration of larvae
Sputum
DIAGNOSIS: A. LUMBRICOIDES
o To confirm Ascaris Loeffler’s pneumonitis
o Demonstration of eosinophils and Charcot-Leyden
crystals
Gastric washings
DIAGNOSIS: A. LUMBRICOIDES
o To confirm intestinal ascariasis
o Highly effective
o Demonstration of eggs (unfertilized or fertilized – not
embryonated in fecal smears)
Direct Fecal Smears
DIAGNOSIS: A. LUMBRICOIDES
o X-ray of abdomen may show the so-called “tramway
sign (railroad track-like)”.
Abdominal X-ray