WORM INFESTATION

MS. CHIBOCHI
ROUND WORMS (Ascariasis)

Ascariasis is a human disease caused by the

parasitic roundworm known as Ascaris
lumbricoides.
Perhaps as many as one quarter of the
world's people are infected, and Ascariasis
is particularly prevalent in tropical regions
and in areas of poor hygiene.
Ascariasis is also called round worm
infection.
Epidemiology

Roughly 1.5 billion individuals are

infected with this worm, primarily in
Africa and Asia.
Ascariasis is endemic in the United States
including Gulf Coast; in Nigeria and in
Southeast Asia.
Causes

Ascariasisis caused by Ascaris

lumbricoides.
Transmission
Itis transmitted to humans by ingestion of
soil contaminated with human feces that
harbors Ascaris lumbricoides ova.
Ingestionmay occur directly (by eating
contaminated soil) or indirectly (by eating
poorly washed raw vegetables grown in
contaminated soil).
RISK FACTORS
The risk factors for roundworm infection
include:
Living in or visiting a warm, tropical
climate
Poor sanitation
Poor personal hygiene
Crowded conditions, such as day care or
institutional settings
Weakened immune system
Malnutrition
Eating undercooked meat
Eating dirt or clay -- children tend to
become infected this way
Contact with animal feces
LIFE CYCLE OF ASCARIASIS
After ingestion of contaminated food or
soil, Ascaris lumbricoides ova enter the
digestive system, and they hatch,
releasing larvae which penetrate the
intestinal wall and reach the lungs through
the bloodstream.
The larvae then circulates in the blood
stream, until they reach in the lungs,
where they break through from the
capillaries into the alveoli where they
larvae grows and molts into juveniles.
Some patients may have pulmonary
symptoms or neurological disorders
during migration of the larvae
After about ten (10) days in pulmonary
capillaries and alveoli, the juveniles then
migrate to the bronchioles, bronchi,
trachea and finally epiglottis.
There, they are swallowed and returned to
the intestine to mature into worms.
In the intestines, the juveniles mature into
adult Ascaris lumbricoides.
The males and females then mate and
fertilization can now occur and the female
produces as many as 200,000 eggs per
day for a year.
They begin producing eggs within 60–65
days of being swallowed.
In larval Ascariasis, symptoms occur 4–
16 days after infection.
The final symptoms are gastrointestinal
discomfort, colic and vomiting, fever, and
observation of live worms in stool.
However there are generally few or no
symptoms.
A bolus of worms may obstruct the
intestine; migrating larvae may cause
pneumonitis and eosinophilia.
These fertilized eggs are then passed out
through feacal matter and become
infectious after 2 weeks in soil; they can
persist in soil for 10 years or more.
This is because the eggs have a lipid layer,
which makes them resistant to the effects
of acids and alkalis as well as other
chemicals.
Life cycle of Ascariasis
Signs and Symptoms

Vague stomach discomfort

Vomiting a worm or passing a worm in stool
Restlessness
Disturbed sleep
Signs of intestinal obstruction
Weight loss
Impaired growth
Fever
Abdominal distension
Diagnosis

The diagnosis is usually incidental when the host

passes a worm in the stool or vomit.
Stool samples for ova and parasites will
demonstrate Ascaris eggs.
Larvae may be found in gastric or respiratory
secretions in pulmonary disease.
Blood counts may demonstrate peripheral
eosinophilia.
On X-ray, 15–35 cm long filling defects,
sometimes with whirled appearance (bolus of
worms).
Treatment

Pharmaceutical drugs that are used to kill

roundworms are called ascaricides and
include:
Mebendazole (Vermox)
Action: Causes slow immobilization and
death of the worms by selectively and
irreversibly blocking uptake of glucose.
Oral dosage is 100 mg 12 hourly for 3
days.
Piperazine:
Action: A flaccid paralyzing agent that causes
a blocking response of Ascaris muscle to
acetylcholine. The narcotizing effect
immobilizes the worm, which prevents
migration when treatment is accomplished with
weak drugs such as thiabendazole. If used by
itself it causes the worm to be passed out in the
feces.
Dosage is 75 mg/kg (max 3.5 g) as a single oral
dose.
Pyrantel pamoate;
Action: leads to depolarization of the
ganglionic and block of nicotinic
neuromuscular transmission, resulting in
spastic paralysis of the worm. Spastic
paralyzing agents, in particular pyrantel
pamoate, may induce complete intestinal
obstruction in a heavy worm load.
Dosage is 11 mg/kg not to exceed 1 g as a
single dose.
Albendazole;
Action: A broad-spectrum antihelminthic
agent that decreases ATP production in the
worm, causing energy depletion,
immobilization, and finally death.
Dosage is 400 mg given as single oral
dose (contraindicated during pregnancy
and children under 2 years).
Other Drugs
Thiabendazole. This may cause migration
of the worm into the esophagus, so it is
usually combined with piperazine.
Hexylresorcinol effective as a single dose,
Santonin,
Nursing Diagnosis

Altered growth and development

Altered nutrition: less than body
requirements
Altered thought processes
Colonic constipation
High risk for fluid volume deficit
High risk for infection
Hyperthermia
Ineffective breathing pattern
Knowledge deficit
Pain
HOOK WORM DISEASE
Introduction
The hookworm is a parasitic nematode
worm that lives in the small intestine of its
host, human.
Hook worm disease is also called
uncinariasis
Hookworm is a leading cause of maternal
and child morbidity in the developing
countries of the tropics and subtropics.
In susceptible children hookworms cause
intellectual, cognitive and growth
retardation, intrauterine growth
retardation, prematurity and low birth
weight among newborns born to infected
mothers.
Hookworm infection is rarely fatal, but
anemia can be significant in the heavily
infected individual.
Epidemiology

It is estimated that between 576-740

million individuals are infected with
hookworm today. Of these infected
individuals, about 80 million are severely
affected.
Causes

Two species of hookworms commonly

infect humans, Ancylostoma duodenale
and Necator americanus.
Necator americanus predominates in the
America, Sub-Saharan Africa, Southeast
Asia, China, and Indonesia.
Ancylostoma duodenale predominates in
the Middle East, North Africa, India
Ankylostomiasis, alternatively spelled
anchylostomiasis is caused when
hookworms, present in large numbers,
produce an iron deficiency anemia by
voraciously sucking blood from the host's
intestinal walls
Helminthiasis, is the disease caused
worm infestation.
Morphology

A. duodenale worms are grayish white or

pinkish with the head slightly bent in
relation to the rest of the body.
They possess well developed mouths with
two pairs of teeth.
While males measure approximately one
centimeter by 0.5 millimeter, the females
are often longer and stouter.
LIFE CYCLE OF HOOKWORMS
N. Americanus and A. duodenale eggs can be
found in warm, moist soil where they will
eventually hatch into first stage larvae.
The feeding non-infective rhabditoform stage,
will feed on soil microbes and eventually molt
into second stage larvae, which is also in the
rhabditoform stage, will feed for approximately
7 days and then molt into the third stage larvae.
This is the filariform stage of the parasite, that
is, the non-feeding infective form of the larvae.
The worm then prnentrates
through the feet of a person and
enters the blood stream.
Eventually, the larvae will enter the lungs
through the pulmonary capillaries and
break out into the alveoli.
They will then travel up the trachea to be
coughed and swallowed by the host.
After being swallowed, the larvae are
then found in the small intestine where
they molt into the adult worm stage.
The entire process from skin penetration to
adult development takes about 5–9 weeks.
The female adult worms will release eggs (N.
Americanus about 9,000-10,000 eggs/day
and A. Duodenale 25,000-30,000 eggs/day)
which are passed in the feces of the human
host.
These eggs will hatch in the environment
within several days and the cycle with start
anew.
Life cycle
Incubation period

The incubation period can vary between a

few weeks to many months and is largely
dependent on the number of Hookworm
parasites an individual is infected with.
Pathophysiology

Hookworm infection is generally

considered to be asymptomatic, but is an
extremely dangerous infection because its
damage is “silent and insidious.”
There are general symptoms that an
individual may experience soon after
infection.
Ground-itch, which is an allergic reaction
at the site of parasitic penetration and
entry, is common in patients infected with
N. americanus.
Additionally, cough and pneumonitis may
result as the larvae begin to break into the
alveoli and travel up the trachea.
Then once the larvae reach the small
intestine of the host and begin to mature,
the infected individual will suffer from
diarrhea and other gastrointestinal
discomfort.
However, the “silent and insidious”
symptoms refer mainly to chronic, heavy-
intensity hookworm infections.
Major morbidity associated with hookworm
is caused by intestinal blood loss, iron
deficiency anemia, and protein malnutrition.
They result mainly from adult hookworms in
the small intestine ingesting blood, rupturing
erythrocytes, and degrading hemoglobin in
the host.
This long-term blood loss can manifest
itself physically through facial and
peripheral edema; eosinophilia and pica
caused by iron deficiency anemia.
It is widely accepted that children who
suffer from chronic hookworm infection
can suffer from growth retardation as well
as intellectual and cognitive impairments.
Signs and Symptoms

The symptoms can be linked to

inflammation in the gut stimulated by
feeding hookworms;
Nausea,
Abdominal pain and intermittent diarrhea
Progressive anemia in prolonged disease:
Capricious appetite,
Pica (or dirt-eating),
Obstinate constipation followed by
diarrhea,
Palpitations, thready pulse, coldness of
the skin, pallor of the mucous membranes,
fatigue and weakness, shortness of breath
Cases running a fatal course, dysentery,
hemorrhages and edema.
Diagnosis

Diagnosis depends on finding

characteristic worm eggs on microscopic
examination of the stools.
Treatment

Albendazole is effective both in the

intestinal stage and during the stage the
parasite is still migrating under the skin.
In case of anaemia, iron supplementation
can cause relief symptoms of iron
deficiency anaemia.
However, as red blood cell levels are
restored, shortage of other essentials such
as folic acid or vitamin B12 may develop,
so this might also be supplemented.
The most common treatment for
Hookworm are Benzimidazoles (BZAs),
specifically albendazole and
mebendazole. BZAs kill adult worms by
binding to the nematode’s β-tubulin and
subsequently inhibiting microtubule
polymerization within the parasite.
In certain circumstances, levamisole and
pyrantel pamoate may be used.
Nursing Diagnosis

Altered growth and development

Altered nutrition; less than body
requirements
Diarrhoea
Fatigue
High risk for fluid volume deficit
High risk for infection
Knowledge deficit
Ineffective breathing pattern
Prevention

The infective larvae develop and survive

in an environment of damp dirt,
particularly sandy and loamy soil. The
main lines of precaution are those dictated
by sanitary science:
Do not defecate in places other than
latrines, toilets etc.
Do not use human excrement or raw
sewage or untreated 'night soil' as
manure/fertilizer in agriculture
Deworm
Hand washing
PIN WORMS

The pinworm genus is Enterobias, also

known as threadworm or Seatworm, is a
nematode and a common intestinal
parasite, especially in humans.
The medical condition caused by
pinworm infestation is known as
Enterobiasis.
Enterobiasis is caused by Enterobias
vermicularis
TRANSMISSION

Pinworms spread through human-to-

human transmission, by ingesting (i.e.,
swallowing) infectious pinworm eggs
and/or by anal insertion.
The eggs are hardy and can remain viable
(i.e., infectious) in a moist environment
for up to three weeks.
After the eggs have been initially
deposited near the anus, they are readily
transmitted to other surfaces through
contamination.
The surface of the eggs is sticky when
laid, and the eggs are readily transmitted
from their initial deposit near the anus to
fingernails, hands, night-clothing and bed
linen.
From here, eggs are further transmitted to
food, water, furniture, toys, bathroom
fixtures and other objects.
Dust containing eggs can become
airborne and widely dispersed when
dislodged from surfaces, for instance
when shaking out bed clothes and linen.
Consequently the eggs can enter the
mouth and nose through inhalation, and
be swallowed later.
Although pinworms do not strictly
multiply inside the body of their human
host, some of the pinworm larvae may
hatch on the anal mucosa, and migrate up
the bowel and back into the
gastrointestinal tract of the original host.
This process is called retroinfection.
When this retroinfection occurs, it leads to
a heavy parasitic load and ensures that the
pinworm infestation continues.
Autoinfection (i.e., infection from the
original host to itself), either through the
anus-to-mouth route or through
retroinfection, causes the pinworms to
inhabit the same host indefinitely.
Epidemiology

The pinworm has a worldwide

distribution, and is the most common
helminth (i.e., parasitic worm) infection.
Pinworms are particularly common in
children. Finger sucking has been shown
to increase both incidence and relapse
rates, and nail biting has been similarly
associated.
Because it spreads from host to host
through contamination, pinworms are
common among people living in close
contact, and tends to occur in all people
within a household.
The prevalence of pinworms is not
associated with gender, nor with any
particular social class, race, or culture.
Pinworm infections are more common
within families with school-aged children, in
primary caregivers of infected children, and
in institutionalized children.
A person is infected with pinworms by
ingesting pinworm eggs either directly or
indirectly. These eggs are deposited around
the anus by the worm and can be carried to
common surfaces such as hands, toys,
bedding, clothing, and toilet seats.
By putting anyone’s contaminated hands
(including one’s own) around the mouth
area or putting one’s mouth on common
contaminated surfaces, a person can
ingest pinworm eggs and become infected
with the pinworm parasite.
Since pinworm eggs are so small, it is
possible to ingest them while breathing.
Once someone has ingested pinworm
eggs, there is an incubation period of 1 to
2 months or longer for the adult gravid
female to mature in the small intestine.
Once mature, the adult female worm
migrates to the colon and lays eggs
around the anus at night, when many of
their hosts are asleep.
People who are infected with pinworm can
transfer the parasite to others for as long as
there is a female pinworm depositing eggs
on the perianal skin.
A person can also re-infect themselves, or
be re-infected by eggs from another person.
In humans, Enterobias vermicularis causes
the medical condition enterobiasis, whose
primary symptom is itching in the anal
area.
Life cycle
The entire life cycle—from egg to adult—
takes place in the human gastrointestinal
tract of a single human host.
The life cycle begins with eggs being
ingested. The eggs hatch in the duodenum
.
The emerging pinworm larvae grow rapidly
to a size of 140 to 150 micrometers in size,
and migrate through the small intestine
towards the colon.
During this migration they molt twice and
become adults. Females survive for 5 to 13
weeks, and males about 7 weeks. The male
and female pinworms mate in the ileum
where after the male pinworms usually die,
and are passed out with stool.
The gravid female pinworms settle in the
ileum, caecum (i.e., beginning of the large
intestine), appendix and ascending colon,
where they attach themselves to the
mucosa and ingest colonic contents.
Almost the entire body of a gravid female
becomes filled with eggs. The estimations
of the number of eggs in a gravid female
pinworm range from about 11,000 to
16,000.
The egg-laying process begins
approximately five weeks after initial
ingestion of pinworm eggs by the human
host. The gravid female pinworms migrate
through the colon towards the rectum at a
rate of 12 to 14 centimeters per hour.
They emerge from the anus, and while
moving on the skin near the anus, the
female pinworms deposit eggs either
through (1) contracting and expelling the
eggs, (2) dying and then disintegrating, or
(3) bodily rupture due to the host
scratching the worm.
After depositing the eggs, the female
becomes opaque and dies. The reason the
female emerges from the anus is to obtain
the oxygen necessary for the maturation
of the eggs.
Treatment

The medications used for the treatment of

pinworm are Mebendazole, Pyrantel pamoate,
and Albendazole.
All three of these drugs are to be given in 1
dose at first and then another single dose 2
weeks later.
The medication does not reliably kill pinworm
eggs. Therefore, the second dose is to prevent
re-infection by adult worms that hatch from
any eggs not killed by the first treatment.
Health practitioners and parents should
weigh the health risks and benefits of
these drugs for patients under 2 years of
age.
Repeated infections should be treated by
the same method as the first infection.
 In households where more than one
member is infected or where repeated,
symptomatic infections occur, it is
recommended that all household members
be treated at the same time.
In institutions, mass and simultaneous
treatment, repeated in 2 weeks, can be
effective.
Prevention & Control

Washing your hands with soap and warm

water after using the toilet, changing
diapers, and before handling food is the
most successful way to prevent pinworm
infection.
In order to stop the spread of pinworm
and possible re-infection, people who are
infected should bathe every morning to
help remove a large amount of the eggs on
the skin. Showering is a better method
than taking a bath, because showering
avoids potentially contaminating the bath
water with pinworm eggs. Infected people
should not co-bathe with others during
their time of infection.
They should also cut fingernails regularly,
and avoid biting the nails and scratching
around the anus.
Frequent changing of underclothes and
bed linens first thing in the morning is a
great way to prevent possible transmission
of eggs in the environment and risk of
reinfection.
TAPE WORMS
Definition
Is the infection of the digestive tract by
adult parasitic flatworms called cestodes
or tapeworms. Live tapeworm larvae
(coenuri) are sometimes ingested by
consuming undercooked food. Once inside
the digestive tract, a larva can grow into a
very large adult tapeworm. Additionally,
many tapeworm larvae cause symptoms
in an intermediate host. For example,
cysticercosis is a disease of humans
involving larval tapeworms in the human
body.
Anatomy
 Scolex ("head") attaches to the
intestine of the definitive host. In
some species, the scolex is
dominated by bothria (tentacles),
which are sometimes called
"sucking grooves", and function
like suction cups. Once docked to
the host intestinal wall, the tape
worm begins to grow a long tail.
Anatomy cont: Body
systems
The main nerve centre of a cestode is
a cerebral ganglion in its scolex. Motor
and sensory innervations depends on
the number and complexity of the
scolex. Smaller nerves emanate from
the commissures to supply the general
body muscular and sensory ending.
The cirrus and vagina are innervated,
and sensory endings around the
genital pore are more plentiful than
other areas. Sensory function includes
both tactoreception and
Anatomy cont: Proglottids
 The body is composed of successive
segments (proglottids). The sum of the
proglottids is called a strobila, which is thin,
and resembles a strip of tape. From this is
derived the common name "tapeworm". Like
some other flatworms, cestodes use flame
cells (protonephridia), located in the
proglottids, for excretion. Mature proglottids
are released from the tapeworm's posterior
end and leave the host in faeces.
 Because each proglottid contains the male
and female reproductive structures, they can
reproduce independently.
Occurrence
Most occurrences are
found in areas which
lack adequate sanitation
and include Southeast
Asia and East Africa.
These are segmented worms whose sizes
vary accordingly to the type of tape
worms.
Types of tape worms

Taenia solium – pork tape worm

Taenia sagnata – beef tape worm
Diphyllobothrium latum – fish tape
worms
Mode of transmission

Taenia saginata, Taenia solium and

Diphyllobothrium latum are transmitted
to humans through ingestion of uncooked
or under cooked beef, pork and fish that
contain tape worm cysts.
Life cycle of tape worms

The tapeworm needs two hosts to

complete its life cycle:
Intermediate host
Such as pigs, cattle and fish. Infection
begins when the host (pig, cattle or fish)
eats faeces infected with tapeworm eggs.
The eggs hatch in the animal’s gut into
embryos (called oncospheres).
These embryos penetrate the wall of the
intestine and are carried in the
bloodstream to tissues, muscles and vital
organs such as the liver, lungs or brain,
where they can develop into watery
‘blisters’ called hydatid cysts.
These cysts contain around 30 to 40
tapeworm heads (the first segment of the
tapeworm).
Definitive host
One gets the infection after eating unproperly
cooked or uncooked meat of pork, beef or fish
which contains larva of tape worms.
The swallowed cysts burst and the tapeworm
heads travel to the gut and attach themselves
to the intestine wall.
The tapeworms are mature after about six
weeks and inhabit the gut of an infected
animal.
Each mature worm grows and sheds the
last segment of its body about every two
weeks. This last segment contains
immature eggs.
The eggs are passed out in faeces. The
eggs are highly resistant to weather
conditions and can remain viable for
months.
The eggs have to be swallowed by an
animal (intermediate host) to form hydatid
cysts.
Signs and symptoms

Diarrhea
Abdominal pains
Abdominal distension
Nausea and vomiting
Nodules in muscle and skin
Weakness
Anorexia
Fatigue
Weight loss
Clinical manifestations cont.
Rarely, worms may cause obstruction of
the intestine. And very rarely, T. solium
larvae can migrate to the brain causing
severe headaches, seizures and other
neurological problems. This condition is
called neurocysticercosis. It can take
years of development before the patient
has those symptoms of the brain.
Diagnosis

Stool sample to identify type of worm

Tissue biopsy if nodules are visible or
palpable
X-ray- cysts calcify and can be seen on x-ray
History of passing segments in stool
Physical examination where cysts will be seen
or palpated
CT scan or MRI may reveal intra cerebral
pathology
Blood test to check for antibodies of worms
Treatment

Niclosamide (Yomesan) – drug of choice.

Give 2g, chew and swallow in an empty
stomach, Give in divided dosages.
Praziquantel
Albendazole
Prevention

Kill the parasite in the original host and stop the

spread of infection by
Having all people use proper toilets at all
times
Meat must be properly inspected for cysticeci
and not sold if cystocerci has been seen.
All meat must be properly cooked.
Good hygiene- proper washing of vegetables,
fruits before eating. Hand washing.