cysticercosis
TRANSCRIPT
CYSTICERCOSIS OPTOM FASLU MUHAMMED
Cysticercosis refers to tissue infection after exposure to eggs of Taenia solium, the pork tape worm.
The disease is spread via the oral route through contaminated food and water, and is primarily a food born disease.
After ingestion the eggs pass through the lumen of the intestine into the tissue and migrate preferentially to the brain and muscles.
Cysticercosis should be differentiated from taeniasis carriage of the adult tape worm in the intestine (which is through ingestion of cysts in an intermediate host, not the ingestion of the eggs as in cysticercosis)
These represents two different stages of the parasite’s life cycle.
Agent: Taenia solium (pork tape worm) The common larval stage of Taenia solium
was also known as cysticercus cellulosa
TRANSMISSON Humans are Taenia solium reservoirs. Eating under cooked pork that contain viable
cysticerci. Large no. of eggs which pass out in the feces The presence of an adult tape worm in the
gut is reasonably harmless. This condition is known as cysticercosis.
LIFE CYCLE
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Two host life cycle Human beings are the only definitive host Both humans and pigs can act as
intermediate host
BASICS OF INFECTION CYCLE Tapeworm larval cyst (cysticercus) is
ingested with poorly infected meat. Larva escapes the cyst and attaches to the
mucosa by the scolex. Feces are contaminated with eggs (persists
for several days in the environment) consumed by pigs (eggs are hatched and form cysticerci)
Humans also can be the intermediate host causing cysticercosis if they ingest eggs.
Two different forms in human:- Human taeniasis Human cysticercosis
Human taeniasis The scolex attaches to the mucosa and
begins forming segments (proglottis) After two months of infection, gravid
proglotids begin to detach from the distal end- excreted in the feces.
Each segment contains 60,000 eggs Worm causes only minor inflammation to the
intestine(mild symptoms- abdominal pain, diarrhoea and naussea)
HUMAN CYSTICERCOSIS Internal auto infection is also possible The invasive oncoshere (embryos) the eggs
are liberated by the action of gastric acid and cross the bowel wall
They estalished at small terminal vessels (muscles, brain, eye) where they grow about the size of 1cm in 2-3 months.
Muscles: small, palpable, movable nodules Chest and arms: mild or no symptoms Ophthalmic cysticercosis: intraocular cysts
floating freely in the vitreous humor, decreased visual acuity
Neurocysticercosis: most symptoms are because of the inflammatory reactions associated with cyst degeneration (that may take years to happen)- epilepsy, hydrocephalus, encephalitis, meningitis
CYSTICERCOSIS IN MUSCLE Cysticerci can develop in any voluntary
muscle in humans Invasion of muscle by cysticerci can cause
myositis, with fever, eosinophilia and muscular pseudo hypertrophy