• BACILLARY DYSENTERY

LEARNING OBJECTIVES
Describe epidemiology of bacillary dysentery
Describe clinical features of bacillary
dysentery
Outline complications of bacillary dysentery
Describe management of bacillary dysentery
Describe prevention and control of bacillary
dysentery
 WHAT IS SHIGELLOSIS?

• Shigellosis is a bacterial infection that affects

the digestive system, caused by a group of
bacteria called Shigella.
• The Shigella bacterium is spread through
contaminated water or food or through contact
with contaminated faeces.
• The bacteria release toxins and damage the
intestines. The primary symptom of shigellosis
is diarrhoea.
 EPIDEMIOLOGY
• An infectious disease spread by contact with a patients or
carriers or through food or water contaminated by their faeces,it
is characterised by bloody stool, fever, vomiting and abdominal
cramps.
• It is known as Shigellosis after the name of the founder of
dysentery bacilli.
• Shigella bacteria cause dysentery throughout the world and are
responsible for 5 to10 percent of all acute diarrhoeal illnesses.
• It is associated with poor sanitation and inadequate water supply.
• It is a contagious infection with episodes of epidemics in
overcrowded populations who have inadequate sanitation.
 CAUSATIVE ORGANISM
• Bacillary dysentery is caused by a non-motile Gram negative
bacilli of Shigella spp .
• There are four spp. of the genus Shigella which cause bacillary
dysentery namely:
• Shigella dysenteriae
• Shigella flexneri
• Shigella boydii
• Shigella sonnei
• Of these, Shigella sonnei, Shigella dysentery and Shigella
flexneri are most frequently responsible for outbreaks.
• Human are the only reservoir for outbreaks. 
 TRANSMISSION
• The Shigellae organism enters the body through the
mouth and then multiplies in the bowel, which
produces a range of symptoms.
• The bacteria appear in the stool of infected people
and are usually spread by person-to-person contact.
• Contaminated food serves as a common source of
infection.
• Flies usually act as mechanical vectors
• The incubation period is 1 – 5 days.
 TRANSMISSION
• Bacilli invade the colonic mucosa and cause the death of intestinal
epithelial cells leading to distortion of the crypts, and formation of crypt
micro-abscesses.
• The inflammatory process may extend through the mucosa to the muscle
layer causing haemorrhage.
• In severe cases complete healing may not occur.
• Resulting in fibrous tissue formation and persistent ulceration.
• Shigella species cause damage by 2 mechanisms:
– Invasion of the colonic epithelium,
– Production of enterotoxin, which enhances virulence.
• Shigella infection produces a self-limited diarrhoeal illness that lasts 5-7
days and may not require antibiotics in individuals who are otherwise
healthy.
 CLINICAL FEATURES

• Frequent bouts of watery diarrhea

• Abdominal cramping, nausea, and vomiting may also occur patients
with shigellosis also have either blood or mucus in their stool, and
they have fever. Fever is frequently present and it may reach 410C
with muscle aches or pain.
• Symptoms usually begin within three days of coming in contact with
Shigella. In some cases, however, symptoms of infection may appear
as much as a week after contact.
• Diarrhea and other signs of shigellosis usually last between two and
seven days. Mild infection lasting a couple of days may not require
treatment. However, staying hydrated in between bouts of diarrhea
is crucial.
 CLINICAL FEATURES
• After 1 or 2 days, many people develop pain on passing
stool, due to painful contractions of the sphincter ani
(tenesmus)
• Accompanied with weight loss and dehydration may become
severe.
• Vomiting is not common but may occur with nausea
accompanied with loss of appetite.
• Severe dehydration that leads to shock and death occurs
mainly in chronically ill adults and children younger than 2
years of age.
• Some children develop febrile seizures.
 DIFFERENTIAL DIAGNOSIS
Bacillary dysentery can • Cryptosporidiosis
mimic: • Escherichia Coli Infections
• Intestinal schistosomiasis • Gastroenteritis, Bacterial
• Amoebiasis • Gastroenteritis, Viral
• Campylobacter Infections • Pseudomembranous Colitis
• Cholera • Salmonellosis
• Clostridium Difficile Colitis • Ulcerative Colitis
• Colon cancer • Yersinia Enterocolitica
Adenocarcinoma
• Crohn Disease
 COMPLICATIONS
• Dehydration. Persistent diarrhea can cause dehydration severe dehydration
can lead to shock and death.
• Seizures. Some children who run high fevers may develop febrile convulsions.
• Rectal prolapse. straining during bowel movements may cause the mucous
membrane, or lining, of the rectum to move out through the anus.
• Hemolytic uremic syndrome. caused by bacteria called E. coli is
characterized by acute haemolysis, renal failure, uraemia, and disseminated
intravascular coagulation .
• Toxic megacolon. This rare complication occurs when colon becomes
paralyzed, preventing one fro having a bowel movement or passing gas. Signs
and symptoms include abdominal pain and swelling, fever, and weakness,
colon may perforate , causing peritonitis, a life-threatening infection
requiring emergency surgery.
 COMPLICATIONS
• Young children and babies who have
dysentery can quickly become dehydrated.
• Shigellosis may cause delirium, convulsions
and coma but little or no diarrhoea.
• This infection may be fatal in 12 to 24 hours.
• Some adults develop eye inflammation and
reactive arthritis (Reiter's syndrome).
 DIAGNOSIS
• Clinical.
• Stools examination stool appears dark red (bloody)
with a lot of mucous.
• Microscopy shows numerous white blood cells
(leucocytes) and many red blood cells
(erythrocytes)
• A positive stool culture for Shigella but this is done
in well equipped hospitals.
• In blood - leucocytosis but anaemia is not common.
 TREATMENT
• Fluids and electrolytes replacement.
• Oral replacement if no dehydration but some
may need parenteral rehydration when there
is severe dehydration.
• In most cases, the disease resolves within 4 to
8 days without antibiotics.
• Severe infections may last 3 to 6 weeks.
 TREATMENT
• Antibiotics of choice are:-
• Trimethoprim -Sulfamethoxazole
• Erythromycin
• The above two drugs are recommended for children or adults.
Other drugs which can be used to treat bacillary dysentery are:
– Ciprofloxacin
– Antibiotics are indicated when the disease is very severe
or when the spread of infection to other people is likely.
– The severity of symptoms and the length of time the stool
contains Shigella can be reduced with antibiotics. 
 PREVENTION AND CONTROL
• Prevention of bacillary dysentery depends on
stopping the faecal-oral transmission .
• Patient Action
• Rehydrate (preferably orally)
• Take antibiotics as prescribed
• Dispose of faeces properly
• Refrain from handling food
 OUTBREAK
• Health Care Provider’s Action
• Improve water supply
• Avoid food contamination.
• Give health education on preparation of
rehydration fluids, use of safe water (boiling),
proper refuse disposal and proper disposal of
faeces.
 DIFFERENCE BETWEEN AMOEBIC AND
BACILLARY DYSENTERY

  Bacillary Dysentery Amoebic Dysentery

Incubation period Short: < 1 week Long: 3 weeks or more
Onset Acute Insidious
Occurrence Epidemic Endemic
Fever Common Only in complications
Clinical picture ‘Lying-down dysentery’ ‘Walking dysentery’
Tenderness Whole abdomen More localised (sigmoid)
Tenesmus Very severe Not usual
Stools    
Macroscopy Mucous and blood only Stool with blood and mucous
Microscopy Numerous red cells Numerous clumped red cells
Numerous polymorphs Polymorphs scanty
Few bacteria Many bacteria
Macrophages E. histolytica trophozoites with
ingested red cells