Parasitology. Created by Tousif Khan. Presented by Suravi Saha Roy, Pranab Karmakar, Rahul Naskar, Subham Karmakar.

1. Taenia solium
DSE 1, Parasitology, SEM 5
Vijaygarh Jyotish Ray College, Zoology Department
Presented by :
Suravi Saha Roy
Tousif Khan
Pranab Karmakar
Rahul Naskar
Subham Karmakar
Date – 30/09/2020

2. General Information
 Common name – Tapeworm
 Scientific name – Taenia solium
 Intermediate Host – Pig
 Definitive Host – Human
 Systematic Position (Ruppert and Barnes, 1994,6th ed)
Kingdom - Animalia
Phylum - Platyhelminthes
Class - Cestoida
Order - Cyclophyllidea
Family - Taeniidae
Genus - Taenia
Species - T. solium
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3. MORPHOLOGY
 Adult :
1) Body is long, whitish, dorso ventrally flattened ribbon like.
2) There are three regions in the body; scolex, neck, strobilla.
3) Scolex is the anterior end, contains 4 cup like suckers. Anterior
region is called rostelum, which contains 20-40 curved chitinous
hooks.
4) Neck is short, narrow and unsegmented.
5) Strobilla is divided into several segments, called proglotids.
6) Each proglotids contains both male and female reproductive organs.
7) In the posterior region there are several gravid proglotids containing
fertilized eggs.
 Cysticercus :
1) It is a bladder like sac filled with a clear watery fluid.
2) The wall of the bladder consists of an outer cuticle and inner
maescenchyme.
3) Present of proscolex.
 Hexacanth :
1) It possesses a pair of penetration gland.
2) It is surrounded by two Hexacanth membranes.
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4. Life Cycle
 Cycle in intermediate host (Pig) :
1. The gravid proglottid excreted with human faeces, containing about 40,000 eggs, are
consumed by pigs.
2. In the duodenum of pig, The outer shell is degraded releasing the 6 hooked oncosphere called
hexacanth, which possesses a pair of penetration glands and is surrounded by two hexacanth
membranes.
3. Then it penetrates the intestinal wall and enters into the bloodstream and reaches the striated
muscle of the pig and becomes encysted in a round covering to become an ineffective
cysticercus.
 Cycle in definitive host (Human) :
1. When man eats improperly cooked pork containing cysticerci, it becomes active in the
intestine. Proscolex turns inside out to form scolex.
2. The scolex anchors to the mucous membrane of the intestine and the neck produces a series
of proglotids to form the strobilla.
3. Both the gravid proglottid and the eggs are released with the feces of infected individuals and
serves as a source of infection for pigs.
4. In some instances an infected individual harboring the adult worm can become auto infected
through the accidental ingestions of eggs released in the faeces.
5. The embryos may transverse the intestinal wall and lodge into the brain.
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6.  Prevalence :
 Epidemiology :
Taenia solium mainly affects the health and livelihoods of subsistence farming communities in
developing countries of Africa, Asia and Latin America. It is common in areas where animal
husbandry practices are such that pigs and cattle come into contact with human faeces.
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In 2015, the WHO Food borne disease burden Epidemiology Reference Group
identified Taenia solium as a leading cause of deaths from food-borne diseases,
resulting in a considerable total of 2.8 million disability-adjusted life-years (DALYs).
Neurocysticercosis is the most frequent preventable cause of epilepsy
worldwide, and is estimated to cause 30% of all epilepsy cases in countries where
the parasite is endemic.

7. Pathogenecity
 Taeniasis (by adult Taenia) :
When the infection is symptomatic, vague abdominal discomfort, indigestion, nausea, diarrhea,
and weight loss may be present. Occasional cases of acute intestinal obstruction, acute
appendicitis, and pancreatitis have also been reported.
 Cysticercosis (by larval stage) :
1. The cysticercus is surrounded by a fibrous capsule except in the eye and ventricles of the
brain.
2. The larvae evoke a cellular reaction starting with infiltration of neutrophils, eosinophils,
lymphocytes,
3. plasma cells, and at times, giant cells. This is followed by fibrosis and death of the larva with
eventual calcification.
4. It may also affect the eyes, brain, and less often the heart, liver, lungs, abdominal cavity, and
spinal cord.
 Neurocysticercosis :
1. It is the most common and most serious form of cysticercosis. About 70% of adult-onset
epilepsy is due to neurocysticercosis.
2. The destruction of parasites induces an inflammatory response, granulomas and fibrous
which may result in a sub acute encephalitis.
3. Other commonly associated clinical manifestations include headache, dizziness, involuntary
muscle movement, intracranial hypertension and dementia.
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8. Diagnosis
1. MRI and CAT scans are considered to be the most sensitive methods of detection
of neurocysticercosis and are useful in establishing diagnosis.
2. Serological methods of detection most often include the ELISA and the ELTB and
involve the detection of antibodies against cysticerci.
3. Other methods of detection include complement fixation and indirect
haemagglutination assay.
Treatment
1. Praziquantel and Albendazole are the two anticysticercal drugs used to treat
patients diagnosed with cysticercosis in the brain and skeletal muscles.
2. Niclosamide (2 g), single dose, is another effective drug.
3. For cysticercosis, excision is the best method, wherever possible.
Prophylaxis
1. Avoidance of eating raw or undercooked pork. The critical thermal point of
cysticercus is 56°C for 5 minutes.
2. Improvement of hygiene and sanitation are highly effective.
3. Altering the infrastructure to keep pigs from roaming freely and contacting human
feces will help to reduce human to pig transmission.
4. Vaccines aimed at preventing infection in pigs may play a role in efforts to control the
spread of disease.
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