2. INTRODUCTION
• Taeniasis in humans is a parasitic infection
caused by the tapeworm species
• Taenia saginata (beef tapeworm), Taenia solium
(pork tapeworm), and Taenia asiatica (Asian
tapeworm).
• Humans can become infected with these
tapeworms by eating raw or undercooked beef
(T. saginata) or pork (T. solium and T. asiatica).
• People with taeniasis may not know they have a
tapeworm infection because symptoms are
usually mild or nonexistent.
3. Introduction cont.
• There are 32 recognized species of Taenia
• Taenia solium (pork tapeworm) and Taenia
saginata (beef tapeworm) are medically
important.
• Recent studies show that Taenia asiatica
infects humans in Southeast Asia
4. • Differentiating between T. solium and T.
saginata infections is important because
infection with T. solium can cause
neurocysticercosis, which is one of the
leading cause of deaths from food-borne
illnesses.
• Cysticercosis caused by T. saginata is
rare; with far lower impact on human health
than T. solium.
6. Epidemiology and Risk Factors
• Taeniasis (T. saginata, T. solium, and T. asiatica)
are found worldwide.
• Eating raw or undercooked beef or pork is the
primary risk factor for acquiring taeniasis.
• Infections with T. saginata occur wherever
contaminated raw beef is eaten, particularly in
Eastern Europe, Russia, eastern Africa and Latin
America.
• Taeniasis due to T. saginata is rare in the United
States, except in places where cattle and people
are concentrated and sanitation is poor,
7. Epidemiology and Risk Factors cont.
• Infection occurs around feed lots when
cattle can be exposed to human faeces.
• Tapeworm infections due to T. solium are
more prevalent in under-developed
communities with poor sanitation and where
people eat raw or undercooked pork.
• Higher rates of illness have been seen in
people in Latin America, Eastern Europe,
sub-Saharan Africa, India, and Asia.
8. Epidemiology and Risk Factors cont.
• A disease called cysticercosis can occur
when T. solium tapeworm eggs are
ingested.
• People with poor hygiene who have
taeniasis with or without symptoms shed
tapeworm eggs in their faeces and might
accidentally contaminate their
environment. This can lead to transmission
of cysticercosis to themselves or others.
9. • All races are equally affected.
• Both genders are equally affected.
• All ages are susceptible to infection. The age
at which raw meat consumption begins is the
primary determinant.
• WHO developed a roadmap for control and
eradication of taeniasis to be implemented in
selected countries by 2020
15. • Scolex of T. saginata.
• four large suckers, lack of rostellum and rostellar
hooks
16.
17. Life cycle
• Adult tapeworms live in the human small
intestine
• Gravid eggs passed in human faeces
mature contaminating pastures and
enviroment.
• Ingested mature eggs upon reaching the
alimentary canal, release the
oncosphere which penetrate the gut wall
and enter the circulation.
• Oncosphere filter from the circulation
and encyst in muscular tissue -
cysticercus larvae becoming infectious
within 2-3 months.
18. • Humans develop a tapeworm
infection by eating raw or
undercooked beef/pork
• The cysticercus becomes activated,
attaches to the wall of the small
intestine by the scolex and becomes
a mature tapeworm.
• This maturation process takes 10-12
weeks & a single tapeworm produces
an average of 50,000 eggs per day
and may live up to 25 years.
19.
20. Morbidity /Mortality
• Most intestinal taeniid infections are
asymptomatic. Mild symptoms occur involve
abdominal pain
anorexia
weight loss & Malaise
• Cysticercosis causes a mass effect in various
vital organs (eg, brain, eye, heart).
• The mortality rate for cysticercosis is low and is
generally caused by complications such as:
encephalitis, increased intracranial pressure
secondary to edema & hydrocephalus, and
21. Pathophysiology & clinical signs
• Passage (active or passive) of proglottids, which
is associated with slight discomfort of colicky
abdominal pain (more common in children).
• Abdominal pain and nausea are reportedly more
common in the morning, and are characteristically
relieved by eating small amounts of food.
• Children are more symptomatic than adults and
often manifest change of appetite, both increased
and decreased.
• Symptoms in infants are more pronounced and
consist of vomiting, diarrhea, fever, weight loss,
and irritability.
22. • The most common serious complication of
adult tapeworm infection include
• Appendicitis
• obstruction of bile ducts & pancreatic duct
• tapeworm growth in ectopic locations (eg,
middle ear, adenoid tissue, uterine cavity).
• Mild eosinophilia (5-15%) may occur in 5-
45% of patients. Taenia infection has been
reported mimicking Crohn's disease.
23. • Cysticercosis and neurocysticercosis (NCC)
• cysticerci are most often located in
subcutaneous and intermuscular tissues,
followed by the eye and then the brain.
• The CNS is involved in 60-90% of patients (ie,
NCC) with most patients have more than one
cyst (as many as 200 cysts )
• NCC symptoms include 3 characteristic
syndromes:
convulsions and/or seizures,
intracranial hypertension
psychiatric disturbances,
• Convulsions and/or seizures: Seizures are
caused by the localization of cysticerci in brain
parenchyma.
24. Children most often present with seizures, which
are focal with acute onset.
Cysticercosis is the most common cause of
epilepsy in endemic areas
• Intracranial hypertension: This is caused by
obstruction of CSF by intraventricular brain
cysts. Symptoms include:
headache, nausea,vomiting,vertigo & papilledema
• Psychiatric disturbances: changes in
personality and mental status occur more often
in adults than in children, behavioral changes
and learning disabilities
25. Physical signs
Most children with intestinal taeniasis appear
healthy.
Weight loss, caused by loss of appetite is
more pronounced in infants than in adults.
Subcutaneous nodules are less common in
children than in adults.
Neurologic abnormalities in some children
with NCC may manifest
Intraocular larva may be evident.
Muscular pseudohypertrophy may occur.
26. Laboratory diagnosis
• Recovery of the following in faecal sample
which are examined microscopically
Ova
Proglittid and Scolex with hooks
32. Treatment and Prognosis
• The following drugs are used
Praziquantel
Niclosamaide
Nitazoxanide
• Post-treatment follow-up stool examination
should be performed after approximately 3
months.
• The prognosis of treated taeniasis is
excellent.
33. Prophylaxis
• Personal hygiene
• General sanitary measures
• Avoidance of ingestion of raw pork or
beef and vegetables irrigated by
sewage water
• Rigid quality inspection of pork and
beef in all slaughter houses
• Healthy education - Avoidance of faecal
contamination
