TISSUE NEMATODES Flashcards
Parastrongylus cantonensis
Also known as
Angiostrongylus cantonensis
Parastrongylus cantonensis
Former name:
Haemostrongylus ratti
Parastrongylus cantonensis
Common Name
Rat Lung Worm
Parastrongylus cantonensis: Life Cycle
Final hosts are ____ (specifically located in their lungs)
rats
Parastrongylus cantonensis: Life Cycle
Female worms in the lungs will produce ____ and these will hatch in the lungs
eggs
Parastrongylus cantonensis: Life Cycle
Once hatched it will release ______ which will then be found in the feces.
L1 larva
Parastrongylus cantonensis: Life Cycle
A related species of P. cantonensis is
_________. They hatch in the small intestine.
costrasinensis
Parastrongylus cantonensis: Life Cycle
L1 larvae will then be ingested by the ____________
intermediate hosts (snails)
Parastrongylus cantonensis: Life Cycle
One of the snails that can serve as Intermediate host is __________
African Giant Snail or Achatina Fulica
Parastrongylus cantonensis: Life Cycle
inside the snail, the L1 larva will become the ______ wherein it is the infective stage
L3 larva
Parastrongylus cantonensis: Life Cycle
The rat will then be infected if they ingest the snail containing the L3 larva or the _____ of the snail.
slime
Parastrongylus cantonensis: Life Cycle
____ are just incidental host if they ingest the snails or vegetables contaminated the by the snail containing the L3 larva or ingesting the paratenic hosts (e.g. crabs or freshwater fishes)
Human
Parastrongylus cantonensis: Life Cycle
Humans will then get the larva and the parasite will find itself in the ____
CNS
Parastrongylus cantonensis: Life Cycle
The larva can also be found in the ____.
eye
Parastrongylus cantonensis
Definitive Host:
Rats (Rattus rattus)
Parastrongylus cantonensis
accidental or incidental host
Humans
Parastrongylus cantonensis
Intermediate Hosts:
○ Achatina fulica (giant African snail)
○ Hemiplecta sagittifera
○ Helicostyla macrostoma
○ Vaginilus plebius
○ Veronicella altae
Parastrongylus cantonensis
Paratenic hosts:
- Prawn
- crab
- vegetation
Parastrongylus cantonensis
Infective stage:
L3 Larva
Parastrongylus cantonensis
MOT:
Ingestion of raw or undercooked infected snails
Parastrongylus cantonensis
Habitat:
Lungs of definitive host
Parastrongylus cantonensis
As of now, we cannot find adult worms yet in ______, they are only in larva stages. However, on rats, we can find adult worms.
humans
Parastrongylus cantonensis
In the female worm, they have the _______ appearance.
“barber pole”
Parastrongylus cantonensis
There are two colors. The darker one represents the _______ of the female worm while the lighter one represents the _________.
- intestine
- uterus
Parastrongylus cantonensis
In the male worm, the lower part shows the ___________ while the tail is called the ______.
- copulatory bursa
- spicule
Parastrongylus cantonensis
infective stage
L3
Parastrongylus cantonensis
Eggs can be recovered in rodent _______
feces
Parastrongylus cantonensis
Parastrongylus cantonensis: Disease
Angiostrongyliasis, Parastrongyliasis
Parastrongylus cantonensis
Parastrongylus cantonensis: Disease Manifestation
Eosinophilic meningoencephalitis
Parastrongylus cantonensis: Disease Manifestation
Signs and Symptoms:
○ Headache
○ Vomiting
○ Neck stiffness
○ Seizures eosinophilia
○ Neurologic abnormalities
○ Ocular involvement wherein the larva are found in the eyes
Parastrongylus cantonensis: Disease Manifestation
Parastrongylus cantonensis: Diagnosis
- Travel History and Exposure of the patient
- Cerebrospinal Fluid (CSF) examination
- CT-Scan
- Serology
- PCR
Parastrongylus cantonensis: Disease Manifestation
Prognosis is good; usually ________
self limiting
Parastrongylus cantonensis: Diagnosis
people usually get this infection if they are coming from endemic areas like __________ and the countries
from the _____________
- Southeast Asia
- Pacific basin
Parastrongylus cantonensis: Diagnosis
more than
______ of WBCs is composed of eosinophils
Cerebrospinal Fluid (CSF) examination
10%
Parastrongylus cantonensis: Diagnosis
CSF Protein:
Cerebrospinal Fluid (CSF) examination
mild elevation
Parastrongylus cantonensis: Treatment
There is still no recommended treatment but the following can be given:
○ Mebendazole
○ Thiabendazole
○ Albendazole
Trichinella spiralis: Life Cycle
There is a life cycle in Trichinella spiralis that would involve a pig to pig life cycle wherein there is ________ that happens
carnivorism
Trichinella spiralis
Commonly known as:
Trichina Worm or Muscle Worm or Garbage worm
Trichinella spiralis: Life Cycle
The pig that would serve as the ________ would ingest meat scraps of animals or meat scraps of pork
final host
Trichinella spiralis: Life Cycle
In this case, the infective stage to the pig which is the final host is the ___________
encysted larva
Trichinella spiralis: Life Cycle
The pigs could get the infection in that manner; if they are ingesting meat scraps or animals containing the _________
encysted larva
Trichinella spiralis: Life Cycle
The rat would ingest meat scraps containing the encysted larva. In some cases, another rat would ingest that rat which was previously infected
rat to rat life cycle
Trichinella spiralis: Life Cycle
Another one is the ________ which involves a host that is carnivorous as well as omnivorous.
Sylvatic life cycle
Trichinella spiralis: Life Cycle
Humans get into the picture if they ingest ____________ containing the encysted larva
undercooked or raw pork
Trichinella spiralis: Life Cycle
It is usually pork that is involved here but in some cases, there are also reports of Trichinella after ingesting __________
animal meat
Trichinella spiralis: Life Cycle
There are also reports of people getting the infection after eating undercooked _________ or ___________
particularly in the United States.
bacon or sausages
Trichinella spiralis: Life Cycle
Once the humans ingest the meat containing the encysted larva, the larva would then be released in the ________ where it develops and becomes adult.
small intestine
Trichinella spiralis: Life Cycle
This larva would then be deposited in the ______ and it would then find its way in the __________
- mucosa
- striated muscle
Trichinella spiralis: Life Cycle
The females in the cycle are __________ females. The female worms produce larva
larviparous
Trichinella spiralis: Life Cycle
The striated muscles that they prefer infecting are those very _____ muscle cells.
active
Trichinella spiralis: Life Cycle
In the encystation process of the larva, ______
are also involved.
nurse cells
Trichinella spiralis: Life Cycle
Aside from the striated muscle, there is also the possibility that the larva can also encyst in the __________ and ____________
- cardiac muscle
- skeletal muscle
Trichinella spiralis: Life Cycle
It helps in producing the cyst that would surround that larva in the muscle
nurse cells
Trichinella spiralis: Life Cycle
If humans get the infection, aside from being an accidental host, they may also serve as the _________ since the life cycle would already stop in humans.
dead end host
Trichinella spiralis
Final Host (FH)
Pigs and other mammals
Trichinella spiralis
Habitat
Small intestine, striated
muscle
Trichinella spiralis
Mode of Transmission
(MOT)
Ingestion of undercooked or
raw pork (other meat) infected with larva
Trichinella spiralis
Infective Stage (IS)
Encysted larva
Trichinella spiralis
Diagnostic stage
Encysted larva
Trichinella spiralis: Adult Morphology
Claspers on tail called:
conical papillae
Trichinella spiralis: Adult Morphology
It holds the female during copulation or
sexual reproduction.
conical papillae
Trichinella spiralis: Adult Morphology
Fully formed _______ with larva
uterus
Trichinella spiralis: Disease Manifestation and Pathology
Signs and Symptoms in intestinal phase
Minor usually nonspecific
gastroenteritis
Trichinella spiralis: Disease Manifestation and Pathology
Disease
Trichinosis
Trichinella spiralis: Disease Manifestation and Pathology
Signs and Symptoms in Muscle Invasion
■ Fever and Eosinophilia
■ High levels of IgE
■ Muscle pain, myocarditis
■ Some may experience CNS
involvement
Trichinella spiralis: Disease Manifestation and Pathology
Another manifestation that you might also encounter in Trichinella is _________
Edema
Trichinella spiralis: Diagnosis
- Muscle biopsy
- Biochemical tests
- Very high levels of eosinophils
- ELISA
- Bentonite Flocculation Test
- Bachman Intradermal Test
- Beck’s Xenodiagnosis
Trichinella spiralis: Diagnosis
A definitive test for Trichinella spiralis. Look for the encysted larva that are usually found in active muscles like the deltoid muscle, the gastrocnemius muscle, and the biceps
Muscle biopsy
Trichinella spiralis: Diagnosis
We can also obtain blood samples and you would notice that there would be elevation of:
Biochemical tests – blood chemistry.
- potassium
- lactate dehydrogenase (LDH)
- myokinase.
Trichinella spiralis: Diagnosis
The elevation of LDH and myokinase is usually associated with _________ of the muscle.
inflammation
Trichinella spiralis: Diagnosis
Trichinella spiralis can actually induce the greatest increase of ___________ among different parasites.
eosinophils
Trichinella spiralis: Diagnosis
A serologic tests that detects your antibodies against Trichinella spiralis:
- ELISA
- Bentonite Flocculation Test
Trichinella spiralis: Diagnosis
Involves the use of laboratory animals,
specifically, albino rats.
Beck’s Xenodiagnosis
Trichinella spiralis: Diagnosis
A skin test wherein you are injected in your skin a _________ dilution of the larval antigen. If you were previously exposed to the parasite, there would be a hypersensitivity reaction, a wheal-and-flare reaction.
Bachman Intradermal Test
1:10,000
Trichinella spiralis: Diagnosis
The muscle coming from the suspected patient is fed into the rat. The rat should be observed for around 14 days. After 14 days, it should be sacrificed and killed.
Beck’s Xenodiagnosis
Trichinella spiralis: Diagnosis
When you have seen a _________ in its small intestine, then the patient is positive for the infection.
Beck’s Xenodiagnosis
female worm
Trichinella spiralis: Treatment
● Mebendazole
● Steroids and Mebendazole
Trichinella spiralis: Treatment
intestinal phase
Mebendazole
Trichinella spiralis: Treatment
severe acute infections
Steroids and Mebendazole
Trichinella spiralis: Epidemiology
Life cycle maintained in the environment by
_________
carnivores
Trichinella spiralis: Epidemiology
Other distinct species of Trichinella spiralis
- T. nativa
- T. nelsoni
- T. britovi
- T. pseudospiralis
Trichinella spiralis: Epidemiology
occurs in arctic and subarctic
zones; high pathogenicity, high resistance to freezing
Other distinct species of Trichinella spiralis
T. nativa
Trichinella spiralis: Epidemiology
occurs in tropical Africa
Other distinct species of Trichinella spiralis
T. nelsoni
Trichinella spiralis: Epidemiology
occurs in temperate Paleoarctic
region; very low pathogenicity
Other distinct species of Trichinella spiralis
T. britovi
Trichinella spiralis: Epidemiology
cosmopolitan; does not
encyst; infectious to birds
Other distinct species of Trichinella spiralis
T. pseudospiralis
Dracunculus medinensis
Commonly known as
- Guinea Worm
- Fiery Serpent
- Medina Worm
- Dragon Worm
Trichinella spiralis: Prevention
Freeze meat in this temp
- -15C for 20 days
- -30C for 6 days
Trichinella spiralis: Prevention
Cook meet in this temp
77C
Largest nematode infecting man
Dracunculus medinensis
Dracunculus medinensis
The female worm of D. medinensis can reach up to __________ in length depending on the references
1-2 meters
Dracunculus medinensis
In the _________ tissue underneath your skin, you can find the adult worms of D. medinensis.
subcutaneous
Dracunculus medinensis: Life Cycle
In the water you would find _________
copepods
Dracunculus medinensis: Life Cycle
Humans get the infection if they are drinking or ingesting contaminated ________
water
Dracunculus medinensis: Life Cycle
Copepods, particularly your cyclops are your
_________.
microcrustaceans
Dracunculus medinensis: Life Cycle
Inside the copepods is the ________. Once the human drinks this water containing the copepods, the person would get the infection.
L3 larva
Dracunculus medinensis: Life Cycle
Eventually, once the person drinks the water containing the copepod, the L3 larva is then released into the _________ which would go to the ___________ and becomes a mature adult worm.
- stomach
- subcutaneous tissue
Dracunculus medinensis: Life Cycle
As the adult worms in the subcutaneous tissue mature, they would eventually _________
reproduce
Dracunculus medinensis: Life Cycle
It would actually take around almost a _____ for the life cycle to continue.
year
Dracunculus medinensis: Life Cycle
After 1 year from the time of infection, the fertilized female worm would then migrate to the skin and subcutaneous tissue causing the formation of blisters
and discharges of _________.
L1 larvae
Dracunculus medinensis: Life Cycle
For the life cycle to continue, that L1 larvae must find its way into __________. Usually it is also the water where they get their drinking water like wells.
fresh water
Dracunculus medinensis: Life Cycle
The adult male worms ___ earlier and are smaller than female worms.
die
Dracunculus medinensis: Life Cycle
Inside the copepod, the L1 larva would eventually become an _________, repeating the life cycle.
L3 larva
Dracunculus medinensis: Life Cycle
If that larva would then have contact with the freshwater, that L1 larva would be ingested by the
______.
copepod
Dracunculus medinensis
Habitat
Subcutaneous Tissue
Dracunculus medinensis
Mode of Transmission
(MOT)
Ingestion/Drinking of
contaminated water
Dracunculus medinensis
Infective Stage (IS) to humans
L3 larva
Dracunculus medinensis
Final Host (FH)
Humans
Dracunculus medinensis
Intermediate Host (IH)
Copepods (Cyclops)
Dracunculus medinensis
Infective Stage (IS) to cocepods
L1 larva
Dracunculus medinensis
This is actually how it is treated or how the worm is removed; by slowly rolling it with the ____________
wooden stick.
Dracunculus medinensis
Make sure that if you’re removing the worm, you have to completely get the whole worm and avoid breaking it because if it is not removed completely, it could also
lead to an __________
allergic reaction.
Dracunculus medinensis
The worm can also ____ in the subcutaneous tissue.
calcify
Dracunculus medinensis: Disease
● Guinea Worm Disease
● Dracunculiasis
Dracunculus medinensis: Disease Manifestation
● Formation of blister
● Urticaria (Itchiness)
● Vomiting, Diarrhea
● Asthma attacks
● Discharge of worm
Dracunculus medinensis: Disease Manifestation
because of the migration of the larva from the GI tract
Vomiting, Diarrhea
Dracunculus medinensis: Disease Manifestation
Symptoms may _______ once ulceration or ulcers/blisters appear
disappear
Dracunculus medinensis: Epidemiology
Usually, the people get the infection if they have contact with the water sources that can be breeding grounds for the copepods like the following:
○ Stepwells of India
○ Wells
○ Ponds
○ Open Cisterns
We primarily find the parasite in:
- Middle East
- Central India Pakistan
- Africa
Dracunculus medinensis: Diagnosis
● Appearance of Cutaneous Lesion and Worms
● X-ray – visualization of calcified worms
Dracunculus medinensis: Treatment
● Removal of worms using a stick
● Metronidazole – drug of choice