Parasitic Disease

about enterobiasis, ascariasis and taeniasis

1. Common Parasitic
Diseases
Lesson 10
MC 3

2. 1. ENTEROBIASIS (also called pinworm, seatworm, or
threadworm infection)
•is a benign intestinal disease caused by the nematode
Enterobius vermicularis.
This photomicrograph depicts the eggs of the
human parasite Enterobius vermicularis via
cellulose tape under significant magnification. All
photographs used are from Centers for Disease
Control and Prevention and the internet.

3. •Enterobius vermicularis is
a small nematode (around
10 mm X 0.7 mm females)
affecting millions
worldwide.
•The pinworm is a white
thread-like worm that
invades the cecum.
•Humans are the only
natural host.
•Fecal-oral contamination
via hand-mouth contact or
via fomites (toys, clothes)
are common methods of
infestation.

4. •After ingestion, eggs hatch in the
duodenumwithin 6 hours, mature
in 2 weeks and have a lifespan of
approximately 2 months.
•Adult worms normally inhabit the
terminal ileum, cecum, vermiform
appendix, and proximal ascending
colon;
•Gravid female worm leaves the
rectum & if not expelled during
defecation, migrates to the
perineum.
•Eggs become infectious within 6-8
hours and in the environment for as
long as 3 weeks.

5. Statistics and Incidences
The incidence of enterobiasisare highest in
school-age children and next highest in
preschoolers.
•Prevalence is approximately 5-15%
in the general population;
•Infestation rate increases with
increased population density;
•E. vermicularis infestation occurs
worldwide;
•Secondary bacterial skin infection
may develop;
•The people most likely to be infected
with pinworms are children younger
than 18 years.

6. Common Symptoms
•Perianal itching.
•Erythema.
•Abdominal pain.
•Visual worm sighting.

7. Assessment and Diagnostic Findings
The usual method of
diagnosis is to use
cellophane tape to capture
the eggs from around the
anus.
Cellophane tape test. The
cellophane tape test for
identifying worms is performed
in the early morning, just
before or as soon as the child
wakens; the tape is then
examined microscopically for
eggs in the laboratory.

8. Medical Management
Treatment of enterobiasis
consists of the following:
•Handwashing.
•Personal hygiene.
Pharmacologic Management:
•Anthelmintics.
-Mebendazole
-Albendazole
-Pyrantel pamoate
•Anal albendazole.

9. Nursing Management.
Nursing care for a child with enterobiasisinclude the following:
Nursing Assessment
•History
Patients with enterobiasisare
often asymptomatic.
If patients are symptomatic,
pruritus ani and pruritus vulvae
are common presenting
symptoms.
•Physical examination
Worms can be found in stools or
on the patient’s perineum before
bathing in the morning.

10. Nursing Diagnosis
Based on the assessment data, the
major nursing diagnoses are:
Risk for impaired skin integrity
related to intense perianal scratching.
Acute pain related to smooth muscle
spasm secondary to migration of
parasites in the stomach.
Imbalanced Nutrition: less than
body requirements related to
anorexia and vomiting.
Hyperthermiarelated to decrease in
circulation secondary to dehydration.

11. Nursing Care Planning &
Goals
The major goals for a child with
Enterobiasisare:
•Reduce discomfort from
perianal itching.
•Diminish pain to a tolerable
level.
•Regain adequate nutrition.
•Reduce or eliminate increase
in temperature.

12. Nursing Interventions
1. Administer medications as
ordered.
2. Inform patient of the side
effects of pyrantel.
3. Improve skin integrity.
4. Diminish pain.
5. Improve hygienic status.
6. Diminish increase in
temperature.

13. 2. Taeniasis(Tapeworm infection)
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)

14. Taenia soliumcan also cause cysticercosis.
Cysticercosisresults
from human ingestion of
T. soliumeggs through
fecal contamination,
reverse peristalsis of
gravid proglottids, or
autoinfection. The
cysticercimay develop
in any organ, and their
effects depend entirely
on the location of the
cysticerci.

15. P
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16. Geographic Distribution
Approximately 50 million people are infected world.
Taenia saginataandTaenia soliumare worldwide in
distribution.
Taenia soliumis more prevalent in poorer
communities where humans live in close contact with
pigs and eat undercooked pork.
Taenia asiaticais limited to Asia and is seen mostly in
the Republic of Korea, China, Taiwan, Indonesia, and
Thailand.

17. Symptoms
Most individuals
with taeniasis are
either
asymptomatic or
have mild-to-
moderate
complaints.
The most common
complaint is
passage (active or
passive) of
proglottids, which is
associated with
slight discomfort.

18. Laboratory Diagnosis
Intestinal Taeniasis
•CBC count detects mild
eosinophilia.
•Examine 3 stool samples
(direct and concentrated
stool preparations)
collected on 3 different
days from patients and
contacts.
Serology
-Copro-Ag ELISA can be used to detect
T. soliumtapeworm carrier with sensitivity
of 84.5% and specificity of 92%.
Molecular analysis
-Copro-PCRhas been used to detect T.
soliumcarrier with sensitivity of 82.7% and
specificity of 99%.
-Multiplex loop-mediated isothermal
amplification (multiplex LAMP) with dot
enzyme-linked immunosorbent assay
(dot-ELISA) help identify human Taenia
species .
-Endoscopy can also help diagnose
taenia infection.

19. Medical Management
Medical Care
Most patients with intestinal Taenia
infection are asymptomatic or mildly
symptomatic.
If adult tapeworms are detected in the
stools, anthelmintic therapy
(albendazole, praziquantel, or both)
are recommended because these
agents provoke an anti-inflammatory
response in the CNS,
glucocorticosteroidsshould be used
in conjunction with antihelmintic
therapy.
Surgical Care
Surgery may be needed if the
infection causes complications such
as acute surgical abdomen,
appendicitis, or obstructed bile or
pancreatic ducts, presence of ocular,
ventricular, & spinal lesions,
Neurocysticercosis, and in some
case of intraventricular cysticercosis,
removal of the cyst can successfully
treat the condition without the need
of antihelmintictherapy.
Surgical excision of ocular
cysticercosisis the preferred method
of treatment.

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21. Prevention & control of T. soliuminfection as recommended by WHO
•Mass drug administration for taeniasis
•Identification and treatment of taeniasis
cases
•Health education, including hygiene and
food safety
•Improved sanitation
•Improved cultivation and production of pig
•Anthelmintic treatment of pigs
(oxfendazole)
•Vaccination of pigs (TSOL18 vaccine)
•Improved meat inspection and processing
of meat products

22. Further Outpatient Care
Following treatment, patients should carefully examine stools for
proglottid elimination during the next 5 weeks for T. solium
infection and for 3 months for T. saginatainfection.
Confirm the efficacy of treatment of T. soliumtaeniasis with history
of proglottids expulsion after 1 week of treatment, microscopic and
macroscopic examination of stool samples 1 month and 3 months
later and if available, obtain CoproAg-ELISA at 1 month and 3
months later. (Repeat treatment if still positive)
Further Inpatient Care
Admit the patient if complications such as intestinal obstruction
arise because of intestinal taeniid infection.

23. Complications
-Appendicitis -Cholecystitis
-Pancreatitis -Intestinal obstruction
-Tubo-ovarian abscess (rare)-Systemic cysticercosis
Prognosis
-Treatment with praziquantel reportedly provides cure rates of 99-100%.
Patient Education
-Educate patients and families about routes of infection and preventive
measures.
-Teach patients and families proper sanitary and personal hygiene
measures.

24. 3. Ascariasis
Ascariasis is the name of an
infection caused by the
roundworms Ascaris
lumbricoidesand Ascaris suum;
when a worm lives inside the
human body, the condition is
called a parasitic infection.
While the vast majority of these
cases are asymptomatic,
infected persons may present
with pulmonary or potentially
severe gastrointestinal
complaints.

25. Pathophysiology
Ascaris lumbricoidesis the
largest of the intestinal
nematodes (roundworms)
affecting humans, measuring
15-35 cm in length in
adulthood that parasitize the
human intestine.
A. lumbricoides is the primary
species involved in human
infections globally, but
Ascaris derived from pigs
(often referred to as A. suum)
may also infect humans.

26. Statistics and Incidences. Intestinal nematode infections affect one
fourth to one-third of the world’s population; of these, the intestinal roundworm Ascaris
lumbricoides is the most common.
•In the United States, approximately 4 million people are believed to be infected.
•High-risk groups include international travelers, recent immigrants (especially from
Latin America and Asia), refugees, and international adoptees.
•Ascariasis is indigenous to the rural southeast, where cross-infection by pigs with
the nematode Ascaris suumis thought to occur.
•Worldwide, 1.4 billion people are infected with Ascaris lumbricoides, with prevalence
among developing countries as low as 4% in Mafia Island, Zanzibar, to as high as
90% in some areas of Indonesia.
•The rate of complicationssecondary to ascariasis ranges from 11-67%, with
intestinal and biliary tract obstruction representing the most common serious
sequelae.
•Although infection with A. lumbricoides is often asymptomatic, it is responsible for an
estimated 730,000 cases of bowel obstruction annually, 11,000 of which are fatal.
•Male children are thought to be infected more frequently

27. Clinical Manifestations
Most patients are asymptomatic. When symptoms occur, they are divided
into two categories: early (larval migration) and late (mechanical effects).
Respiratory symptoms. Classically, these symptoms occur in
the setting of eosinophilic pneumonia (Löfflersyndrome): fever,
nonproductive cough, dyspnea, wheezing.
Gastrointestinal symptoms. Typically related to the mechanical
effects of high parasite loads; passage of worms (from mouth,
nares, anus), diffuse or epigastric abdominal pain, nausea,
vomiting, pharyngeal globus, “tingling throat”, frequent throat
clearing, and dry coughare some of the GI symptoms.

28. Assessment and Diagnostic Findings
Diagnosis of roundworms is confirmed through the following:
•Complete blood count (CBC) may show eosinophilia.
•Sputum analysis may reveal larvae or Charcot-
Leyden crystals.
•Stool examination findings include presence of ova.
•Chest radiography may reveal patchy infiltrates of
eosinophilic pneumonia.
•Abdominal radiography may reveal signs of bowel
obstruction.
•On computed tomography (CT) scanning, Ascaris
worms may be visualized as linear or cylindrical filling
defects.
•Using point-of-care emergency department
ultrasonography (POCUS) is also used in the
diagnosis of ascariasis.

29. Medical Management. Treatment is divided according to the phases
of infection: early infection (larval migration) and established infection.
Benzimidazolesare the mainstay of
treatment of symptomatic and
asymptomatic infections; the most
common members of this family are
albendazoleand mebendazole.
Bowel obstruction. Treatment of bowel
obstruction includes intravenous hydration,
nasogastric suctioning, electrolyte
monitoring, and laparotomyif conservative
measures fail; colonoscopyand
esophagogastroduodenoscopy(EGD) may
be useful in removing obstructing masses
of worms.

30. Pharmacologic Management
Medications used to treat roundworms include:
•Albendazole. Decreases ATP production in worm, causing energy depletion,
immobilization, and finally death.
•Mebendazole. Causes worm death by selectively and irreversibly blocking
uptake of glucose and other nutrients in the susceptible adult intestine where
helminths dwell.
•Piperazine citrate. Recommend for GI or biliary obstruction secondary to
ascariasis; causes flaccid paralysisof the helminth by blocking the response
to worm muscle to acetylcholine.
•Pyrantel pamoate. Depolarizing neuromuscular blocking agent; inhibits
cholinesterases, resulting in spastic paralysis of the worm.
•Ivermectin. Binds selectively with glutamate-gated chloride ion channels in
invertebrate nerve and muscle cells, causing cell death.
•Levamisole. May inhibit worm copulation via agonism of L-subtype nicotinic
acetylcholine receptors in male nematode muscles.

31. Prevention & Control
The best way to prevent people from getting ascariasis from humans or pigs is to always
do the following:
•Avoid ingesting soil that may be contaminated with human or pig feces, including
where human fecal matter (“night soil”), wastewater, or pig manure is used to fertilize
crops.
•Wash your hands with soap and water before handling food, after touching or
handling pigs, cleaning pig pens, or handling pig manure.
•Teach children the importance of washing hands to prevent infection.
•Supervise children around pigs, ensuring that they do not put unwashed hands in
their mouths.
•Wash, peel, or cook all raw vegetables and fruits before eating, particularly those
that have been grown in soil that has been fertilized with manure.
Transmissionof Ascaris lumbricoides infection to others in a community setting can be
prevented by: Not defecating outdoors &
Implementation of effective sewage disposal systems.

32. Nursing Assessment
Assessmentof the child include:
History. Soil-transmitted worm infections,
including roundworm, are among the most
common infections worldwide; they affect poor
and deprived communities, where there is
overcrowding and poor sanitation; most
recorded cases of roundworm are contracted
abroad, either by travelers or migrants who
come from parts of the world where
roundworm is present.
Physical exam. General symptoms include
fever, jaundice, cachexia, pallor, and urticaria;
pulmonary symptoms include wheezing, rales,
and diminished breath sounds; GI symptoms
include abdominal tenderness, distention,
nausea, and vomiting.
Nursing Diagnosis
Based on the assessment data, the
major nursing diagnoses are:
Fluid volume deficit related to fluid
loss secondary to diarrhea.
Impaired sense of comfort: pain
related to smooth muscle spasm
secondary to migration of parasites
in the stomach.
Imbalanced Nutrition: less than
body requirements related to
anorexia and vomiting.
Hyperthermiarelated to decrease
in circulation secondary to
dehydration.

33. Nursing Interventions
Nursing interventions for a child with roundworm include the following:
•Improve fluid and electrolyte balance. Monitor intake and output of fluids;
observe signs of dehydration; give oral rehydration solution to assist in adequate
hydration; observe accurate intravenous fluid administration.
•Reduce pain and discomfort. Assess the extent and characteristics of pain; give
a warm compress on the abdomen; teach a method of distraction to reduce
pain; set a comfortable position that can reduce pain.
•Improve nutrition. Give adequate and nutritious food; measure body weight
every day; explain the importance of adequate nutrition, and maintain good oral
hygiene.
•Maintain normothermia. Teach the client and family the importance of
adequate feedback; monitor fluid intake and output; monitor the temperature
and vital signs; provide tepid sponge baths, and administer analgesics as
indicated.