2. 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.
3. 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.
4. Agent: Taenia solium (pork tape worm)
The common larval stage of Taenia solium was
also known as cysticercus cellulosa
5. 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.
8. Two host life cycle
Human beings are the only definitive host
Both humans and pigs can act as intermediate host
9. 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)
10. Humans also can be the intermediate host causing
cysticercosis if they ingest eggs.
Two different forms in human:-
Human taeniasis
Human cysticercosis
11. 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)
12. 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.
13. 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
14. 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