This document provides information about bacillary and amoebic dysentery. It defines dysentery as passing blood and mucus in stool with abdominal pain. It discusses the objectives, types, magnitude, epidemiological features, pathophysiology, clinical features, assessment, treatment and prevention of bacillary dysentery caused by Shigella bacteria and amoebic dysentery caused by Entamoeba histolytica. Key differences between the two types are also summarized. The document aims to educate about the infectious diseases.

1. Ms. Chanda Jabeen
PhD (Scholar) Epidemiology & Public Health
1
Dysentery
Bacillary & Amoebic

2. OBJECTIVES
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At the end of this presentation we will be able to
 Define dysentery
 Define magnitude of problem
 Explain epidemiological features
 Explain the pathophysiology
 Enlist clinical features
 Describe assessment
 Discuss preventive measures

3. Dysentery
3
Dysentery means passing of blood and mucus in
stools, accompainied by abdominal pain with or
without tenesmus. (This condition should not be
confused with passing of blood per anal canal due to
other reasons)
TYPES OF DYSENTERY:
The two main form of dysentery are:
1: Bacillary dysentery (Bacterial)
2: Amoebic dysentery (protozoal)

4. Magnitude of problem
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 Bacillary dysentery is an acute infection of the bowel,
which is characterized by diarrhoea.
 This disease is more common in infants than in
adults.
 This infection is transmitted through contaminated
food especially milk and water , by carrier or patients
suffering from dysentery.
 This disease is prevalent in many parts of world
specially orients, tropics and subtropics.

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 It is a common disease accurring in all ages and
causing many deaths.
 Death rates are higher in small children, though its
susceptibility is general.
 A relative and transitory strain specific immunity
occur after an attack of this disease.
Communicability:
The period of communicability is during acute
infection when faeces contain microorganism.

6. Epidemiological features
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Agent:
There are various species of the genus shigella that
causes bacillary dysentery. These are known as
shigella shiga,s.sonnei and others.
Some strains of shigella produce few carriers of
disease for 1 to 2 years and in rare cases ever longer

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Host:
1. Age:
Most common in children between the age 6months to
2 years than adults.

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i. Sex: Both sexes are affected.
ii. Season: It is common in rainy season.
iii. General: Low resistance of the body that is when a
person is weak and had a low resistance then he suffers
from this disease more than the healthy person.
iv. Environmental factors:
 Community with environmental sanitation
(contaminated food and water)
 Soil pollution, low standard personal hygiene, lack of
education and poor quality of life.

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Source of infection:
Main source is faeces of infeacted person .
Incubation period:
May be as short as few hours as long as 7 days, but
average period is of 7 to 14 days
Mode of infection:
Consuming contaminated food, milk and water.
By using articles which are ontaminated with faeces
of carrier.

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Flies spread the disease by contaminating food
articles.
Hand to mouth transfer of contaminated food
material is the direct mode of infection.
Pathophysiology:
In severe cases shigellosis reaching the small
intestine where they multiply and release a toxin that
initiate secretion of water and electrolytes from
jejunal area.

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The invading pathogens are capable of initiating an
intense inflammatory response in the mucosa
followed by small patches of ulceration causes
diarrhoea with blood and mucus in the stool.
Clinical Features:
1. Patient has diarrhoea, fever and tenesmus.
2. Patient become restless, temp rises up to 103ºF
and increase pulse rate
3. Tongue become dry and coated.

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4 .Signs of dehydration and collapse.
5. In small children regidity of abdominal muscles due
to contractions.
6.Toxaemia due to endo and exotoxins.
7. Increase number of stools up to 20 or more in 24
hours, in severe cases jelly like substance is seen in
the blood.
8. Infants ,elderly debilitated persons infected by
shigella bacillus most frequently have severe
infection.

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Assessment:
 By sign and symptoms of disease.
 Important sign is presence of blood in the stool with
jelly like substances.
 It must be differentiated from other types of
diarrhoea and dysenteries.
 Microscopic examination of fresh stool
 Rectal swab examination also shows the presence of
dysentery bacilli.

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Preventive Measures:
 Immunization against measles is a potential
intervention for diarrhoea control.
 Sanitation measures to reduce transmission
emphasis the traditional improved water supply.
 Improved excreta disposal and improved domestic
and food hygiene with adequate supply of clean
water.
 Protect and purify public water supply. People
should drink boiled water during epidemic season

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 Milk and milk product should be pasteurised
properly before use.
 Control of flies by using screened doors and
windows, protect food from contamination.
 Report about the patient to the health authorities.
 Patient must be isolated until his/her report comes
as negative.
 Patient should not be allowed to handle any food
articles ,until he recovers.

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 All the contacts of patient must take personal
precautions.
 Faeces of patient must be collected, disinfected and
disposed off properly.
 Health education about practicing personal and
environmental hygiene.

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Specific Treatment:
 Tetracycline antibiotics, such as aureomycin,
terramycin and streptomycin, if given parenterally
will reduce symptoms rapidly.
There is also marked reduction in the bacilli within
24 to 48 hours and freedom from infection in several
cases/day.
 Streptomycin especially sulphadiazine is also
effective in these cases.

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 Turpentine oil stupes may be given to relieve
distention of abdomen.
 Starch and opium enema may be given to control
pain and diarrhoea.
 To relieve pain morphine inj may be given.
 Some authorities give antidysentery serum in severe
cases of shigella shiga infection.
 If all treatment fails, the urgency may be done to give
rest to large intestines of patient.

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Introduction:
Amoebiasis is a worldwide parasitic disease
Which is responsible for multiple medical surgical
problems. It is caused by protozoa Entamoeba
histolytica and is acquired by ingestion of cyst stage
of E histolytica, in food or water contaminated by
infected human faeces.
AMOEBIC DYSENTERY

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Magnitude of problems:
It is most common endemic infection of man in most
regions of the world. In US it is found in rural
areas or in most of patients who have lived or
travelled in the tropics, generally limited or warm
regions.
The term “amoebiasis” has been defined
as the condition of harbouring the protozoan
parasite Entamoeba histolytica with or without
clinical manifestations.

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The symptomatic group has been further subdivided into
intestinal and extraintestinal amoebiasis.
Epidemiological Features:
Agent:
Amoebiasis is a common infection of human GIT caused by
Entamoeba histolytica.
Morphology:
Amoebiasis is caused by potentially pathogenic strains of E
histolytica. Recently other pathogenic amoebae have
been identified and include Acanthamoeba hartmanella
and Naegleri.

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E hystolytica exist in two forms.
1. Trophozoite
2. Cyst

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25. E. hystolytica Cyst
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Trophyzoites:
Size varies from 10 to 40 microns. Trophozoite is
actively motile and seen in acute amoebic
dysentery stools under microscope. Infection is not
transmitted from person to person. Trophyziotes
are demonstrated in faeces of acute amoebic
dysentery.

27. Cyst
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 Trophozoites undergo encystment in the large
intestine of man. Cysts are 10 to 15 micron in sizes.
 when mature cysts contaminating food or water are
ingested by man, it may result in amoebic infection.
 Cysts are demonstrated in cyst passer. These are
never seen in extraintestinal amoebiasis.
 Clinical illness is characterized by mucus diarrhoea,
steatorrhoea, epigestric pain and malabsorption

28. Host
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i. Age: Amoebiasis may occur at any age.
ii. Sex: There is no sex or racial in the occurence of
disease. It is a household infection. When any
individual in a family is infected, other members of
family may also be affected.
iii. Environmental factors:
Amoebiasis is more closely related to poor sanitation
and socio- economic status than to climate.The
use of night soils for agricultural purposes, favours
the spread of disease.

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 In countries with marked wet dry seasons, infection
rate is higher during rains.
 Endemic outbreak potential for transmission is,
thereby increased.
 Epidemic outbreaks are usually associated with
sewage seeping into water supply.
Mode of infection:
As same for bacillary dysentery.

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Incubation period:
The incubation period is about 3 to 4 weeks. In the
face of massive infection the incubation period may
be shorter.
Pathophysiology :
The amoeba gain their way into intestinal mucosa
where they feed mainly on bacteria. Pus pocket may
form with only a small orfice into the bowel from
which numerous burrows.

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 External for considerable distances in all directions
under the mucous membrane and eventually slough
off, exposing an underlying ulcer that may enlarge to
size of 1 to 2 cm in diameter.
 The large bowel may be so covered by such ulcers
that the little normal mucus membrane is left.
 Usually the floor of these ulcers is the muscle well of
the bowel but they may perforate its entire water and
cause fatal peritonitis.

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 In the small intestine the organism may erode
intestinal mucosa, invade the blood stream and gain
an access to liver through portal
Clinical Features:
May be symptomatic or asymptomatic
1. Colicky abdominal pain
2. Diarrhoea: watery foul smelling stool containing
blood streaked mucus.

33. Prevention and control
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Primary prevention:
1. Sanitary disposal of human excreta.
2. Provision of safe and adequate drinking water,
boiled water.
3. Hygienic kitchen practice
4. Thourough washing of uncoocked fruits and
vegetables.
5. Protection of food against flies.

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6. Health education of people about personal hygiene,
proper toilet habits such as hand washing after
defaecation and controlling insects.
Secondary Prevention:
 Early diagnosis
 Immunodiagnostic techniques such as agar gel
diffusion test,
 latex agglutination test and counter electrophoresis
test.

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Treatment:
The advent of flagyl has revolitionised the treatment
of amoebic dysentery. The adult dose is 800 mg
thrice daily for 5 to 7 days.
Mass Treatment:
National programmes:
Diarrhoeal disease control programme:

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Difference Between Bacillary &
Amoebic Dysentery

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Bacillary dysentery Amoebic dysentery
1. Onset usually acute. 1.Onset insidious.
2.Fever and toxemia
commonly present.
2. Fever and toxemia
uncommon.
3. Number of stools many in 24
hours.
3. Number of stools 4 to 6 in 24
hours
4.Intestinl colic severe. 4. Intestinal colic present, but
not severe.
5. Severe tenesmus usual. 5. Tenesmus rare.
6. Stools: scanty, containin
bright red and viscid pink
coloured mucus.
6.Stools: copious, mixed with
blood and mucus.
7.Stool odourless. 7. Stools offensive.
8. Reaction of stool alkaline. 8. Reaction of stool acidic.
9.Whole abdomen rigid and
tender especially lower
9. Local rigidity and
tenderness over sigmoid colon

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Bacillary Dysentery Amoebic Dysentery
10. Microscopic examination of stools
shows polymorphonuclear cells,
RBCS, macrophages epithelial cells
and degenerated endothelial cells.
10. Microscopic examination of stool
shows RBCS, damaged
polymorphonuclear cells, many
macrophages, Entamoeba histolytica
and charcol laden crystals.
11. Average type subsides within 10-
14 days.
11. Cource long or protracted.
12. Complication infrequent in severe
infection, circulatory failure, renal
failure, arthritis and eye
complications may occur.
11. Complications may be of hepatitis
and lower abscess.
13. Culture of stools reveal dysentery. 13. Culture of stool for dysentery
organism negtive.
14. Serological diagnosis by
agglutination reaction positive.
14. Serological diagnosis by
agglutination.
15. Respond well to sulphonamides
and antibiotics.
15. Respond well to emetic.

39. REFRENCES
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Basvanthapa,B.T.(2008).Delhi,India.Medical
Publisher private LTD