CYSTICERCOSIS Flashcards
What is cysticercosis?
- a tissue infection caused by exposure to the eggs of Taenia Solium
- It is acquired via the feco-oral route through food or water
*Consumption of inadequately cooked pork
- Fecally contaminated food or water as well as self contamination by reflux
- After ingestion the eggs pass through the lumen of the intestine into the tissue and migrate preferentially to the brain and muscles.
In cystecicercosis, the human represents an intermediate host and the parasite develops cysticerci in various organs
What is Taeniasis and Cysticerci?
Taeniasis: infection caused by the adult tapeworm in the human intestine, which occurs from ingestion of larvae in undercooked pork
Cysticerci: larval forms of tapeworms found within a fluid filled cyst
The larvae can develop into cysts in various parts of the body, including the muscles, brain, and eyes, causing a range of symptoms.
Pathogenesis of cysticercosis
The eggs hatch in the intestine and the oncospheres burrow through the wall into the blood vessels.
They can disseminate to various organs which include the brain, eyes where they encyst to form cysticerci
Sites of cysticerci, symptoms and how they cause problems?
What is the most common site of infection
?
The pathology of cysticercosis depends on:
In humans, cysticerci can develop in various tissues such as muscle,skin, eyes, and the central nervous system (CNS).
The CNS is the most common site of infection and can cause severe pathology.
In the brain, the larvae can develop into cysticerci cysts, which are fluid-filled sacs surrounded by a fibrous capsule.
The cysts can cause inflammation and pressure on the surrounding tissues, leading to a range of neurological symptoms such as headaches, seizures, cognitive impairment, and even death.
The pathology of cysticercosis depends on the location, number, and size of the cysticerci, as well as the host’s immune response.
What is believed to be responsible for 30 percent of all epilepsy cases, making it the primary preventable cause of epilepsy globally?
NCC - Neurocysticercosis
The pathological changes in the brain due to cysticercosis are often divided into four stages:
vesicular, colloidal, granular, and calcified.
cysticercosis can also affect the eye, leading to a condition known as
ocular cysticercosis
The larvae can develop in the eye, causing inflammation and damage to the retina, leading to vision loss.
Results of Cysticercosis
Cysticercosis may result in palpable nodules in the muscles and subcutaneous tissues, which may be misidentified as tumors.
In exceptional circumstances, the cysts can relocate to other organs such as the heart, lungs, liver, and spleen, causing pathological alterations in those areas.
Clinical presentation of cysticercosis
Depends on the site
Space occupying lesion in the brain which can manifest as seizure
Subcutaneous nodule in the skin
Headaches.
Confusion.
Difficulty with balance.
Discuss the phases of pathological changes in the brain due to cysticercosis
The vesicular stage is characterized by the presence of small cysts, which are often asymptomatic.
In the colloidal stage, the cysts become larger and more inflamed, leading to neurological symptoms.
In the granular stage, the cysts start to degenerate, causing a chronic inflammatory response.
The cysts harden and are frequently evident on imaging tests during this stage.
Cystic cavity contains the larval form: scolex with hooklets and 2 pairs of suckers
The larval form, composed of duct-like invaginations, is lined by a double layered, eosinophilic membrane
Scolex is single and invaginated; contains a rostellum, 4 suckers and 22 - 23 bifrefringent hooklets (may persist for a long time)
Body wall exhibits a myxoid matrix and calcareous bodies (calcified concretions)
Cysticerci may remain viable for years
Colloidal stage: first stage of involution of cysticerci; transparent vesicular fluid is replaced by a turbid, viscous fluid and the scolex shows signs of hyaline degeneration
Granular stage: cysticercus is no longer viable; cyst wall thickens and the scolex is transformed into coarse mineralized granules
Host inflammatory reaction is usually not present if the larva is viable
Finally, a granulomatous reaction develops characterized by histiocytes, epitheloid cells and foreign body giant cells, leading to fibrosis of the supporting stroma and calcification of the parasitic debris
Main Cysticercosis Diagnosis & Tests
• lab test: Antibody test
• imaging studies :
Soft tissue X-rays
brain CT scans
MRI of brain
• Procedures:
Lumbar puncture: CSF tests
Biopsy of the affective area
subcutaneous nodule
Treatment
Albendazole
Praziquantel
Good hygiene practices and proper cooking of meat
