A part 2 of my previous slide.

1. Helminthic Diseases of the
Digestive System
A Powerpoint presentation by Jess Christian B. Pacot

2. Helminthic Diseases of the Digestive
System
● Very common to human intestinal tract
● More common on places with poor sanitation
● In spite of their size and formidable appearance,
they often produce few symptoms. They have
become so well adapted to their human hosts,
and vice versa, that when their presence is
revealed, it is often a surprise.

3. Tapeworms
● Life cycle of a typical tapeworm:
– Adult worm lives in the intestine of a human host, where it produces eggs that are
excreted in the feces…
– The eggs are ingested by animals such as grazing cattles or pigs, where the egg
hatch into a larval form called a cystecercus…
– Infect humans by consuming uncooked or raw meat of the infected cattle or pig.
● Tapeworms like Taenia solium, Taenia saginata and Diphyllobothrium latum
cause tapeworm infection to humans.
● Adult tapeworms can be undiagnosed in a human.
● Diagnosis is based on the observation of proglottids and eggs in feces.
● Symptoms like abdominal pain, vomiting, nausea, enteritis, diarrhea, weight
loss are caused by tapeworm infection.
● It would cause Taeniasis (adult tapeworm infects human intestine),
Cysticercosis (infection with the larval stage), ophthalmic cysticercosis and
neurocysticercosis.

5. Hydatic disease
● Caused by one of the most dangerous tapeworms, Echinococcus granulosus. The disease
occurs most frequently in people who raise sheep or hunt or trap wild animals.
● Humans infested with the tapeworm Echinococcus granulosus might have hydatid cysts in
their lungs or other organs.
● If the cyst ruptures in the host, it can lead to the development of a great many daughter
cysts. Another factor in the pathogenicity of such cysts is that the fluid contains
proteinaceous material to which the host becomes sensitized. If the cyst suddenly ruptures,
the result can be life-threatening anaphylactic shock.
– *Anaphylactic shock is an extreme, often life-threatening allergic reaction to an antigen to which the body has become hypersensitive.
● For diagnosis, several serological tests that detect circulating antibodies are useful in
screening. If available, physical imaging methods such as X rays, CT, and MRI are best.
● Treatment is usually surgical removal, but care must be taken to avoid release of the fluid
and the potential spread of infection or anaphylactic shock. If removal is not feasible, the
drug albendazole can kill the cysts.

8. Nematodes
● Pinworms
– Caused by Enterobius vermicularis. This tiny worm migrates out of the anus
of the human host to lay its eggs. Which cause local itching.
– Diagnosis is usually based on finding eggs around the anus.
– Such drugs as pyrantel pamoate (often available without a prescription) and
mebendazole are usually effective in treatment.
● Hookworms
– The hookworm attaches to the intestinal wall and feeds on blood and tissue
rather than on partially digested food, so the presence of large numbers of
worms can lead to anemia and lethargic behavior.
– Heavy infections can also lead to a bizarre symptom known as pica, a craving
for peculiar foods, such as laundry starch or soil containing a certain type of
clay. Pica is a symptom of iron deficiency anemia.
– Hookworm infections are diagnosed by finding parasite eggs in feces and can
be treated effectively with mebendazole.

9. Ascariasis
● One of the most widespread helminthic infection
● Caused by Ascaris lumbricoides
●
These worms can be quite large, up to 30 cm (about 1 ft) in length.
In the intestinal tract, they live on partially digested food and cause
few symptoms.
●
In the lungs, the tiny larvae may cause some pulmonary symptoms.
Extremely large numbers may block the intestine, bile duct, or
pancreatic duct. The worms do not usually cause severe symptoms,
but their presence can be manifested in distressing ways.
● Microscopic examination of feces for eggs is used for diagnosis.
Once ascariasis is diagnosed, it can be effectively treated with
mebendazole or albendazole.

11. Whipworm Infestation (Trichuriasis)
● Caused by Trichuris trichiura.
● The worm lives there for several years as a
tissue parasite, feeding on cell contents and
blood.
● It causes abdominal pain and diarrhea. It can
also lead to malnutrition.
● Treatment is with mebendazole or albendazole,
although most cases do not require medical
attention.

12. Trichinellosis
● Trichinellosis is caused by a small roundworm called Trichinella spiralis.
● Ingesting undercooked pork is probably the most common mode of
infection but eating the flesh of animals that feed on garbage is an
increasing cause of outbreaks.
● Freezing pork for prolonged periods (for example, −23°C for 10 days) kills
T. spiralis. However, freezing does not kill some species found in wild
game, such as Trichinella nativa.
● Symptoms of trichinellosis include fever, swelling around the eyes, and
gastrointestinal upset. Small hemorrhages under the fingernails are often
observed.
● Biopsy specimens and serological tests are used for diagnosis. Treatment
of administering albendazole or mebendazole kills the intestinal worm.