TAENIASIS OR CYSTICERCOSIS
Etiology
• Caused by Taenia solium(pork tapeworm) and Taenia saginata (beef tapeworm).
• These are present in the small intestine of humans and can live in human intestine for
many years.
• Adult tapeworm contains 800-900 proglottids.
• Eggs of Taenia can survive for about two months in summer and for 5 months in
winter conditions.
Differences between T.solium and T.saginata
Characteristic
Taenia solium Taenia saginata
features
Definitive host Man and rarely dogs Man
Intermediate
Pigs and man Cattle
hosts
Intermediate Cysticercus cellulosae (Measly
Cysticercus bovis (Measly beef)
stage (larvae) pork)
Heart, diaphragm, internal
masseter, tongue, neck, Masseter, shoulder, esophagus,
Predilection
intercostals and abdominal heart, tongue, diaphragm, liver,
sites
muscles, less commonly brain, lung and lymph nodes
liver, lung, kidney and eye
Taeniosis, Cysticercosis
Taeniasis
Disease in man Autoinfection is possible in man
and man can act as complete No autoinfection in humans
host
Reservoirs and incidence
• Human beings are universally susceptible to taeniasis.
• Infection is more common in low socio-economic group of the people.
• Use of untreated sewages for irrigation.
• Coprophagus insects and birds feeding on sewage water may disseminate infection to
distance places.
Transmission
• Humans get the infection through ingestion of raw or under cooked meat and meat
products infested either with Cysticercus cellulosae (Measly pork) or Cysticercus
bovis (Measly beef).
• Auto-infection also cause infection in case of Taenia solium infection.
Disease in humans
Taenia solium infection
• The incubation period is about 8 to 14 weeks. The infection is usually subclinical,
however, in clinical cases; it is characterized by abdominal pain, anorexia, nausea,
diarrhoea and constipation, loss of body weight and debility. Nervousness and
insomnia may also occur.
• Cysticercosis is more serious than taeniasis in humans. It recognized as:
– Myocysticercosis: Muscular cramps, pain and muscle fatigue.
– Ocular cysticercosis: Presence of cysticerci in vitreous humor and anterior
chamber of eyes leads to uveitis, iritis, retinitis and palbebral conjunctivitis.
- Neurocysticercosis:
• Signs depend on the location of the cyst found on the brain.
• Usually it found in the meninges, cerebral cortex and ventricles. So, symptoms
of meningitis, epileptic encephalitis, headache, ataxia, nausea, vomiting and
visual disturbances may be observed.
• Increased intracranial pressure and space occupying lesions.
• Abnormal psychiatric manifestations also observed.
Taenia saginata infection
• Taenia saginata taeniasis produces mild abdominal symptoms and may cause
malnutrition. (Epigastric pain, vomiting, diarrhea)
• The most striking feature consists of the passage (active and passive) of
proglottids.
• The patients may find gravid proglottids themselves and take the segments for
diagnosis to the doctors.
• Occasionally, appendicitis or cholangitis can result from migrating proglottids.
Disease in animals
• Animals act as intermediate hosts, in which the infestations are described as
Cysticercus cellulosae (Measly pork) and Cysticercus bovis (Measly beef).
Diagnosis
Taeniasis
• Anal swab: to find egg at perianal region
• Fecal exam: to find segment (species identification)
Cysticercosis
• Biopsy (subcutaneous nodule)
• X-ray/CT/MRI/electroencephalogram(EEG) / BRAIN SCAN arteriography: cerebral
cysticercosis
• Ophthalmoscopy: ophthalmic cysticerci
• Serological tests:-
• Indirect HA
• Indirect FA
• Precipitation test
• ELISA
Treatment
• Praziquantel for cysticercosis
• Niclosamide or dichlorophen for taeniasis
Prevention and control
• Complete cooking of beef or pork.
• Strict post-mortem inspection and proper disposal of affected meat.
• Freezing of meat at -20C for 10 days which can kill the cystecerci
• Thorough washing of fruits and vegetables before consumption.
• Avoid night soiling.
• Maintain personal hygiene (washing hands always before eating).
• Treatment of sewage before disposal is important.
• Don’t allow coprofeeding of pigs.
• Chemoprophylaxis to kill adult parasites in the human intestine.
• Public health awareness.
