3. A parasitic species of ciliate protozoan that causes the
disease Balantidiasis.
Balantidium coli is the largest protozoan and the only
ciliate known to parasitize humans.
5. Trophozoite
•Oval pointed at anterior end
•50-130um long
•Covered in cilia
•motile
• Non-infective
• Reproduce by binary fission
and conjugation
• Micronuclei and macronuclei
6. Cyst
•Smaller than trophozoites
•Spherical
• 40-60um across
•Non motile
• Covered with thick,hard
•Faintly yellowish green in
color
cyst wall with cilia made of
one or two layers
•Infective
• Non-reproductive
•Macronuclei
7. Transmission
Fecal-oral route
Eating meat, fruits, and vegetables that have been
contaminated by an infected person or contaminated
by fecal matter from an infected animal
Drinking and washing food with contaminated water
Having poor hygiene habits
8. Life cycle
Life Cycle Completed in a single host Natural hosts
Pigs Accidental host
Route : Ingestion
Reproduction: asexual and sexual
10. Life cycle
Balantidium coli has 2 developmental stages: a
trophozoite stage and a cyst stage.
The cyst is the infective stage of Balantidium coli life
cycle.
Once the cyst is ingested via feces-contaminated food
or water, it passes through the host digestive system.
There, excystation takes place in small intestine.
Excystation produces a trophozoite from the cyst
stage.
11. Life Cycle
The motile trophozoite then resides in the lumen of the large
intestine, feeding on intestinal nutrients.
Trophozoites multiply by asexual binary fission or sexual
conjugation.
The trophozoite may become invasive and penetrate the
mucosa of the large intestine.
Trophozoites are released with the feces, and encyst to form
new cyst.
Encystation takes place in the rectum of the host as
feces are dehydrated or soon after the feces have been excreted.
Cysts in the environment are then ready to infect another host.
12. Clinical Presentation of Balantidiasis
Trophozoites can invade the mucosa of the large
intestine (cecum and colon) and cause ulcerations.
The parasite secretes a substance called hyaluronidase
enzyme, which helps degrade intestinal tissue and
facilitates penetration of the mucosa.
Other bacteria in the intestine may enter the ulcer
along with Balantidium coli, leading to secondary
infections. Ulcerations of the large intestine can be
viewed using sigmoidoscopy
13. symptoms
Acute ,even hemorrhagic
Diarrhea
Ulceration to gut wall
Dysentery
Colitis
Abdominal pain
14. Epidemiology
Balantidiosis is most often found in tropical regions
throughout the world ,It is not a common human
disease;
The infection rate is less than 1% ,The parasite is
nonpathogenic in pigs and is much more prevalent
(20-100%) among these hosts.
Pigs are a good source of infection for humans in areas
where they share habitation.
15. Diagnosis
Examination of patient`s stool
A stool sample is collected and a wet mount is
prepared
Biopsy
sigmoid scope is used to visually inspect the last
sections of the large intestine