(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
DIAGNOSIS: A. LUMBRICOIDES
o Can also be requested and may show the string sign,
wherein the adult worms ingest the contrast material.
o Adult worms that passed out in the anus or in the
mouth can be a sign of erraticism.
Barium swallow
TREATMENT: A. LUMBRICOIDES
DOG
drug of choice
Albendazole and mebendazole
100 mg BID for 1-3 days
TREATMENT: A. LUMBRICOIDES
OTHER drugs
- PIPERAZINE CITRATE (75 mg) per kg OD for 2 days
- PYRANTEL PAMOATE (11 mg) per kg in single dose
TREATMENT: A. LUMBRICOIDES
For heavy infestation
surgery may be required to remove worms, such as Ascaris bolus and repair damage they’ve caused like intestinal perforations, bile duct blockage, and appendicitis.
TREATMENT: A. LUMBRICOIDES
Drainage may also be done for?
Liver abscess
Prevention: A. LUMBRICOIDES
ANU
- Proper and hygienic methods of human waste disposal
- Prohibit use of human feces (night soil) as fertilizer in
vegetable gardens - Care for foods and water from contamination with fecal
material - Control of insects that may serve as mechanical
transmitters, such as flies and cockroaches - Provision of safe drinking water
SECERNENTEA: UN-ADAPTED WORMS
Identify
- TOXOCARA CANIS AND CATI
- ANISAKIS SPECIES
consist of species that are UNABLE TO REACH ADULTHOOD IN THE HUMAN HOST BUT, can cause disease in man.
Un-adapted worms
SECERNENTEA: UN-ADAPTED WORMS
Disease among humans is labeled as
visceral larva migrans
owing to the ability of the larval stages to cause significant and potentially serious pathology in various internal organs
SECERNENTEA: UN-ADAPTED WORMS
It is the presence of migrating larval stages of a
particular worm in the visceral organs of the body.
Visceral Larva Migrans (VLM)
SECERNENTEA: UN-ADAPTED WORMS
most common
Toxocara canis
TOXOCARA CANIS AND CATI
Dog ascarid
T. canis
TOXOCARA CANIS AND CATI
cat ascarid
TOXOCARA CATI
TOXOCARA CANIS AND CATI
adult worms inhabit the intestines of?
dogs or cats
TOXOCARA CANIS AND CATI
TOF. Humans are accidental hosts.
T
LIFE CYCLE: TOXOCARA CANIS AND CATI
Definitive host
animals
LIFE CYCLE: TOXOCARA CANIS AND CATI
What is shed out of the feces?
unembryonated eggs
LIFE CYCLE: TOXOCARA CANIS AND CATI
Where does the eggs will embryonate and become infective?
environment
LIFE CYCLE: TOXOCARA CANIS AND CATI
TOF. The adult worm will be developed and oviposit in the small intestine.
T
LIFE CYCLE: TOXOCARA CANIS AND CATI
MOT
fecal-oral route
LIFE CYCLE: TOXOCARA CANIS AND CATI
Infective stage
Embryonated egg
LIFE CYCLE: TOXOCARA CANIS AND CATI
egg hatches in the small intestine and the larva that escapes from the egg penetrates the intestinal walls to go into the?
MESENTERIC VENULES
LIFE CYCLE: TOXOCARA CANIS AND CATI
larval form reaches different sites through the
blood circulation
LIFE CYCLE: TOXOCARA CANIS AND CATI
Organs invaded
liver (most common), lungs, brain, and eyes
LIFE CYCLE: TOXOCARA CANIS AND CATI
TOF. The larva does not develop into the adult stage in the human body.
T
They will become adults in the small intestine of dogs/cats
LIFE CYCLE: TOXOCARA CANIS AND CATI
If the larva goes into the eyes, the condition is referred to as
ocular larva migrans
LIFE CYCLE: TOXOCARA CANIS AND CATI
TOF. Ocular larva migrans typically occurs only in one eye and can cause irreversible vision loss
T
LIFE CYCLE: TOXOCARA CANIS AND CATI
present in the liver
hepatitis
LIFE CYCLE: TOXOCARA CANIS AND CATI
Main manifestations of toxocariasis
VLM and OLM
LIFE CYCLE: TOXOCARA CANIS AND CATI
present in the lungs
pneumonia
PATHOLOGY AND CLINICAL MANIFESTATIONS: T. cati and canis
Migration of larvae causes eosinophilic inflammation that result to
granuloma formation
severity of which depends on the number of larvae, the type of tissue invaded, and the duration of the infection
PATHOLOGY AND CLINICAL MANIFESTATIONS: T. cati and canis
TOF. most striking clinical feature of human toxocariasis (or VLM) is high, sustained increase of eosinophils (eosinophilia)
T
PATHOLOGY AND CLINICAL MANIFESTATIONS: T. cati and canis
CHARACTERISTIC TRIAD OF THE INFECTION
o Marked eosinophilia
o Hepatomegaly
o Hyperglobulinemia
DIAGNOSIS: T. cati and canis
enumerate
Microprecipitation test
ELISA (confirmatory)
Tissue biopsy (if present in diff parts of the body)
Treatment: T. cati and canis
ENUMERATE
- Drugs used for treatment include thiabendazole and corticosteroids.
- Albendzole
- The infection may be prevented through protecting
children from contact with infected dogs, these animals
should be de-wormed regularly, and do not allow
domestic pets to defecate promiscuously.
Anisakis species causes?
Anisakiasis or Herring Worm Disease
Anisakis sp.
MOT
Ingestion of 3rd stage larva (L3) in undercooked fish
Anisakis sp.
Clinical manifestation
instestinal obstructuon
Anisakis sp.
Infective stage to definitive host
L3 larvae
Anisakis sp.
Diagnostic stage
Anisakiasis (larva)
Anisakis sp.
Adult worm inhibits
Stomach of marine mammals
Anisakis sp.
Where do they embryonate
body of water
the larva stage is developed there
Anisakis sp.
When it dies, where does it go?
muscle tissues
Anisakis sp.
Incidental host
Humans
Anisakis sp.
Laboratory diagnosis
- serologic
- gastroscopy (larva)
- surgery (biopsy)
Anisakis spp
Treatment
Albendazole and/or surgery