3. What is Entamoeba histolytica?
•take from a few days to a
few weeks to develop and
manifest themselves, but
usually it is about two to four
weeks
•(histo –lytic = tissue
destroying) is
an anaerobic parasitic proto
zoan, part of the genus
Entamoeba. Predominantly
infecting humans and other
primates.
4. What is Entamoeba histolytica?
•can actually 'bore' into the
intestinal wall, causing lesions
and intestinal symptoms, and it
may reach the blood stream
•it can reach different vital
organs of the human body,
usually the liver, but
sometimes the lungs, brain,
spleen, etc
•A common outcome of this
invasion of tissues is a liver
abscess, which can be fatal if
untreated
5. What are the symptoms?
• Mild diarrhea to severe
dysentery with blood and mucus
• fulminating dysentery
• weight loss
• Fatigue
• abdominal pain
• amoeboma
6. How is it transmitted?
• by the fecal-oral route
• indirectly through contact with dirty hands
or objects
• by anal-oral contact
• through contaminated food and water
7. Diagnosis
• By finding cysts shed in the stool
through flotation or sedimentation
procedures.
• Serological tests
• Microscopy (fecalysis)
8. How to prevent?
• To help prevent the spread of
amoebiasis around the home :
– Wash hands thoroughly with
soap and hot running water for
at least 10 seconds after using
the toilet or changing a baby's
diaper, and before handling
food.
– Clean bathrooms and toilets of
ten; pay particular attention
to toilet seats and taps.
– Avoid sharing towels or face
washers.
• To help prevent infection:
– Avoid raw vegetables when
in endemic areas, as they
may have been fertilized
using human feces.
– Boil water or treat
with iodine tablets.
– Avoid eating street foods
especially in public places
where others are sharing
sauces in one container
9. What can be done to prevent amoebiasis?
• It is important to be careful about food in tropical countries where all forms
of travelers' diarrhea may occur.
• Avoid food that may have been cooked some time before. Freshly boiled
food, eg, rice and sweet corn, is safe to eat.
• Avoid salads, shellfish, crab and prawns
• Avoid fruit and vegetables which can't be peeled; fruits which can be peeled,
eg, avocado, bananas, citrus fruits and melon, are safe
• Do not have ice in drinks and drink only bottled water. Do not use tap water,
even for brushing teeth
• If a traveler has spent a long time in tropical countries, it may be advisable
for them to have a stool test on returning home as amoebae may be present
without symptoms and require treatment.
Good sanitary practice, as well as responsible sewage disposal or treatment,
are necessary for the prevention ofE.histolytica infection on an endemic
level. E.histolytica cysts are usually resistant to chlorination, therefore
sedimentation and filtration of water supplies are necessary to reduce the
incidence of infection
10. What treatment is available?
• If there are no symptoms but a stool sample confirms the presence of amoebic cysts,
medical treatment will be prescribed. A 10-day course ofdiloxanide tablets is given to
eradicate the parasite in carriers with no symptoms.
Metronidazole (eg, Flagyl®), a type of antibiotic, may be given (as tablets or as syrup) for
amoebic dysentery or liver abscess or for other forms of amoebic disease. It may also be
given to eradicate the parasite in carriers with no symptoms.
Tinidazole (Fasigyn®) is another antibiotic which may be given for amoebic dysentery or
amoebic liver disease as an alternative to metronidazole. Tinidazole is given as tablets.
Diloxanide may be given alone for chronic (long-lasting) infections or after a course of
treatment with metronidazole or tinidazole to destroy any amoebae in the intestine.
Chloroquine tablets (as Avloclor®) may be used to treat amoebic hepatitis.
Rehydration is very important. Electrolyte solutions can be taken to replace fluid and
salts that are lost as a result of the diarrhoea. Rehydration preparations include
Dioralyte®, Electrolade® and Rapolyte®. Plenty of clear liquids such as water or juice
should also be drunk.
An ameboma, also known as an amebic granuloma, is a rare complication of entamoeba histolytica, where in response to the infecting amoeba there is formation of annular colonic granulation, which results in a large local lesion of the bowel.