Lecture 3 Dr.Jabar Al-Autabbi
Blastocystosis
(Blastocystis
'hominis' Infection)
What isBlastocystosis
Blastocystosis is an illness
caused by a microscopic
parasite, Blastocystis
hominis' (also known
as Blastocystis 'hominis'
hominis).
parasite lives in the intestine
and is passed in feces.
Because the parasite is
protected by an outer shell, it
can survive outside the body
and in the environment for
long periods in some cases.
Once a person or animal has
been infected with Blastocystis
'hominis', the parasite lives in
the intestine and is passed in
feces.
During the past 2
decades, Blastocystis
'hominis' infection has become
recognized as a common cause
of waterborne disease in
humans in the United
States.Blastocystishominis' can
be found worldwide and within
every region of the United
States.
T
How do you get
Blastocystosis and
how is it spread?
The Blastocystis
'hominis' parasite lives in the
intestine of infected humans or
animals (e.g., cats, dogs, pigs,
horses, cattle)
Millions of germs can be
released in a bowel
movement of an infected
human or
animal. Blastocystis
'hominis' is found on
surfaces or in soil, food, or
water that has been
contaminated with the
feces from infected humans or
animals. You can become
infected after accidentally
swallowing the parasite;
you cannot become infected
through contact with blood.
Blastocystis 'hominis' can be
spread by:
Accidentally
swallowing Blastocystis
'hominis' picked up from
surfaces (such as bathroom
fixtures, changing tables,
diaper pails, or toys)
contaminated with feces from
an infected person or animal.
Drinking water or using
ice made from
contaminated sources
(e.g., lakes, streams,
shallow [less than 50
feet] or poorly
monitored ormaintained
wells)
.
Swallowing recreational
water contaminated
with Blastocystis
'hominis'. Recreational
water includes water in
swimming pools, water
parks, hot tubs or spas,
fountains, lakes, rivers,
springs, ponds, or streams
that can be contaminated
with feces or sewage from
humans or animals.
Eating uncooked food
contaminated
with Blastocystis 'hominis'.
Having contact with someone
who is ill with Blastocystosis.
Traveling to countries where
Blastocystosis is common and
being exposed to the parasite
as described in the bullets
above.
What are the
symptoms of
Blastocystosis?
Blastocystis 'hominis' infection
can cause a variety ofintestinal
signs or
symptoms,whichinclude
Abdominal pain
Diarrhea
Constipation
Gas or flatulence
Greasy stools that tend
to float
Upset stomach or
nausea
Patients also report fatigue, skin rashes, and
joint pain. Some people with Blastocystis
'hominis'infection have severe symptoms,
while others have no symptoms at all.
. In this class of disease,
researchers have found that
people with more severe
symptoms may be infected
with more virulent types of
microbes, and also may have a
genetic makeup which causes
the microbe to produce more
severe illness.
How long
afterinfection do
symptoms appear?
That is difficult to say. In
animal studies, symptoms of
Blastocystosis appear within
two weeks after becoming
infected.
In humans, some people
may have few symptoms
when initially infected, but
the symptoms may become
worse over a period of
months or years.
How long will symptoms last?
In some patients, Blastocystosis is an
acute illness, meaning that symptoms
will last for a short time (several weeks)
In other patients, the disease
may become chronic, and
symptoms will last
indefinitely. Researchers are
working to understand why
some infections produce chronic
illness, while others clear on
their own.
Who is most likely
to get
Blastocystosis?
Anyone can get Blastocystosis.
Persons more likely to become
infected include
International travelers
.
.
Close contacts (such as those
in the same family or in the
.same household or child care
setting) or caregivers of
infected people
.
People who drink water or
use ice made from
contaminated sources (e.g.,
lakes, streams, shallow or
poorly monitored or
maintained wells).
Contaminated water may
include water that has not
been boiled, filtered, or
disinfected with chemicals.
Children in child care settings,
including diaper-aged children.
Backpackers, hikers, and
campers who drink untreated or
insufficiently treated water or
who do not practice good
hygiene (e.g., proper hand
washing
People who swallow
contaminated water while
swimming, especially in lakes,
rivers, springs, ponds, and
streams. Several community-
wide outbreaks of Blastocystosis
have been linked to drinking
water contaminated
with Blastocystis 'hominis'.
People exposed to human feces
through sexual contact
What should I do if I think I
may have Blastocystosis?
Contact your health care provider.
How is
a Blastocystis
'hominis' infection
diagnosed?
Your health care provider will
likely ask you to submit stool
samples to check for the
parasite. .
Because Blastocystis
'hominis' can be difficult to
diagnose, your provider
might ask you to submit
multiple stool specimens
collected over a few
days. Even in that case,
the diagnostics may fail to
detect the infection.
. Researchers have developed
more reliable diagnostics, but
those are not widely available to
patients. BRF is working to
make more reliable diagnostics
available to patients.
What is the
treatment for
Blastocystosis?
There is no FDA approved
treatment for Blastocystis
'hominis' infection. Physicians
have reported success in some
patients with
several prescription drugs, but
the success rates for treatment
of Blastocystis 'hominis' are
much lower than for other
diseases. Many patients
remain symptomatic after
treatment.
My child does not have
diarrhea, but was recently
diagnosed as
havingBlastocystis
'hominis' infection. My health
care provider says treatment is
not necessary. Is this true?
Because treatments are
unreliable, it may not be
appropriate to treat an
asymptomatic
patient. Researchers and
patients have also reported
that symptoms began after
antibiotic treatment, so it is
possible that antibiotic
treatment could make an
individual case worse.
If my child or I have
been diagnosed with
Blastocystosis, should I
worry about spreading
the infection to others?
Yes, Blastocystis
'hominis' infection can be
very contagious. Follow
these guidelines to avoid
spreading Blastocystis
'hominis' to others:
Wash your hands with soap
and water after using the
toilet and before handling
food. Use of a fingernail
brush to clean under the
fingernails may help.
Do not swim in recreational
water (pools, hot tubs, lakes,
rivers, the ocean, etc.)
while you have diarrhea and
for 1 week after your diarrhea
stops. You can
pass Blastocystis 'hominis' in
your feces and contaminate
the water after your symptoms
have stopped.
Avoid fecal exposure during
sexual activity. This is
especially important while
experiencing diarrhea caused
by Blastocystosis.
Use a barrier during oral-anal
sex.Wash hands immediately
after handling a condom used
during anal sex or after
touching the anus or rectal
area.
How can I prevent
a Blastocystis
'hominis' infection?
Practice good hygiene
1.Wash hands thoroughly with
soap and water.
After using the toilet and
before handling or eating
food, especially while having
diarrhea.
After changing a diaper or
assisting with tioleting,
especially if you are caring
for diaper-aged children,
even if you are wearing
gloves.
.
After touching something that
could be contaminated (such
as a trash can, cleaning cloth,
drain, or soil).
After handling animals or their
toys, leashes, or feces
1.Assist or visually
supervise young children
and other people you are
caring for with hand
washing as needed.
Protect others by not
swimming if you are
experiencing diarrhea and
for 1 week after your
diarrhea stops. This is
essential for children in
diapers.
Shower with soap and
water before entering
recreational water. Wash
children thoroughly,
especially their bottoms,
with soap and water after
they use the toilet or their
diapers are changed and
before they enter the water.
1.rivers, the ocean, etc. by
taking the following steps
Take children on frequent
bathroom breaks or check
their diapers often.
Change diapers in the
bathroom or a diaper-
changing area.
Avoid water that might
be contaminated.
