Amoebiasis is caused by the intestinal endoparasite Entamoeba histolytica, leading to symptoms such as diarrhea, dysentery, and liver abscesses, particularly prevalent in regions like Mexico, China, and India. The infection is transmitted through contaminated food and water, with the presence of trophozoites indicating infection, while treatment options include anti-malaria drugs and metronidazole. Prevention strategies involve personal hygiene practices, proper sanitation, and avoiding contamination in food and drinking water.

1. Shri Shivaji Education Society, Amravati's
Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly. Dist. Buldana
Topic: Amoebiasis
Class: B.Sc-I, Sem-I
Shantaram Bhoye
Assistant Professor, Department of Zoology
M.Sc., NET-JRF, SET, M.A.(Eng.)

2. Amoebiasis:
 Entamoeba histolytica is intestinal endoparasite of man, causing diarrhea, dysentery,
hepatitis, liver abscesses, etc. in man, are collectively termed amoebiasis.
 Infection is high in Mexico, China, India and Parts of South America.
 Endoparasite commonly found in the colon region of large intestine.
 In its life cycle complete three distinct forms.
1) Trophozoite or Magna form:
 It is most active, motile and feeding form which is pathogenic to man.
 It lives in the mucosa and submucosa layers of large intestine of man.
2) Prycystic or Minuta form:
 It is small spherical, non motile and non motile and non feeding.
 It lives in the lumen of large intestine and is non pathogenic to man.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana

3. 3) Cystic form:
 During cystic stage or minuta form
becomes rounded and becomes surrounded
by thin, flexible, colourless and
transparent cyst wall.
Infection to new host:
 Infection to new human host occurs by
taking contaminated food, vegetables or
drinking contaminated water, containing
mature quadrinucleate cysts.
 The untreated human faeces in open
ground and vegetable fields is the common
source of infection.
 Unhygienic food handlers, flies,
cockroach, birds, etc. also convey the
infection to unprotected food stuffs.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana

4. Symptoms of Amoebiasis:
1) Dysentery:
 The trophozoites of E. histolytica secrete proteolytic enzyme, histolysin which causes
dissolution and necrosis of mucosa and submucosa of the large intestine.
 These areas of infection are called ulcers and they bleed profusely pouring mucous, cell debris,
blood corpuscles, bacteria and amoeba into the lumen of large intestine and pass outside with
stool.
 The stool is usually acidic.
 The person suffering from amoebic dysentery has repeated blood mixed slimy and foul smelling
motions.
2) Ulcers:
 In the colon wall becomes perforated and millions of bacteria are liberated into the abdominal
cavity, where they cause infection peritonitis which frequently results in death.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana

5. 3) Chronic amoebiasis:
 The patient usually suffers from diarrhea, bowel irregularities, pseudo constipation, abdominal
pain, headache, nausea, loss of appetite, nervousness, fatigue, etc.
 The person continues to live his normal life without problems, but serves as a carrier of the
disease.
4) Abscesses:
 Sometimes, the trophozoites reach to other parts of the body, such as liver, brain, lungs, spleen,
gonads, etc.
 Here also, they cause destruction of tissues forming abscesses (cavities containing pus).
i) Liver abscesses:
 Liver becomes enlarged, congested and painful to touch is referred to as amoebic hepatitis.
 The patient has fever, pain in liver and loss of appetite.
ii) Lung abscesses:
 Usually rupture into the bronchial tube and discharge brown mucoid material which is
coughed out with sputum.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana

6. iii) Brain abscesses:
 Sometimes the parasite also forms abscesses in brain.
 Lung and brain abscesses usually prove fatal.
Diagnosis:
 The microscopic examination of stool of an infected man shows the presence of trophozoites
or stones in it.
 The presence of white, stone shaped Charcoal-Leyden crystals in faeces suggests E.
histolytica infection.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana

7. Treatment (Therapy):
 The anti-malaria drug chloroquine is effective against abscesses in liver.
 Some of the iodine compounds such as Vioform, Chinioform, Diodoquin, etc. may be given orally
and found more effective in eradication of the parasite.
 The use of Metronidazole and Tinidazole in the treatment of amoebiasis.
 It is very effective against both intestinal and extra intestinal amoebiasis.
Prevention (Prophylaxis):
A) Personal prophylaxis:
 Washing hands with soap and water after handling dirty articles after using toilet and before taking
meals.
 Cutting finger nails regularly.
 Use of boiled drinking water or aqua filtered water and properly washed fruits, vegetables
 And raw salads.
 Protection of foods and drinks from contamination by house flies, cockroaches, etc.
 Avoiding defecation on open grounds, streets or vegetable fields.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana

8. Community prophylaxis:
 Proper sanitation of open drains, roads, streets and lanes.
 Protection of drinking water supplies from faecal pollution.
 Covering of food articles by hawkers.
 Proper disposal of sewage.
 Detection and isolation of carriers.
Mr. Shantaram Bhoye, Assistant Professor, Shri Pundlik Maharaj Mahavidyalaya, Nandura Rly., Dist. Buldana