Download Typhoid fever

Typhoid fever
You Chengcheng
Dept. of pathology
China Three Gorges University
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Contents
Introduction
 Pathogenesis
 Pathological changes
 Symptoms
 Complication

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First, let me tell
a story of typhoid Mary
……
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Prevalent in the third world country
Outbreaks are rare,but in some areas such as in
Indonesia and New Guinea,it ranks among the 5
most common causes of death
Bacterial infection of the intestinal tract and
occasionally the bloodstream
The ileum is most affected
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Mononuclear Phagocytic System(MPS):
Monocytes and its derivations
mononuclear cells (blood)
macrophages (connective tissue)
kupffer cells (liver) ………..
Typhoid fever is characterized by macrophages
Proliferation of MPS, which are particularly
predominant in ileum.
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Pathogenesis
The germ that causes typhoid is a unique
human strain of salmonella called Salmonella
typhi
Gram negative bacillus.
O-Ag, H-Ag, vi-Ag
(Widal reaction)
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Infection source：typhoid fever patient and carrier
route of transmission： fecal-oral route
susceptible population:children and young people
Food, fly, finger, water
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second contact
First contact
Salmonella typhi
Contaminanted food
Proliferate in
ileum tissue bacteremia
Whole body
Lymph tissue
Septicaemia
in ileum
Toxemia
Gall
bladder
Excretion
Incubation period(10 d)
Hyperplasia stage
(1w)
Necrosis and ulceration
(2w)
Healing
(1w)
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Pathological changes
Hallmark histologic finding:the infiltration of tissue
by typhoid cells
typhoid cells:large macrophages contain
Phagocytized erythrocytes, lymphocytes,
bacteria and necrotic cellular debris
Typhoid nodule (typhoid granuloma) :
the aggregates of typhoid cells
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Typhoid nodule can present in the lymph tissue
of small intestine, mesenteric lymph node, the
liver, spleen and marrow,
its typical changes often occur in the lower
part of ileum , especially in the Peyer‘s
patches and Isolated lymphonodulus.
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typhoid cell
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typhoid cell
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typhoid cell
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typhoid cell
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Typhoid granuloma
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Intestinal pathological changes
The principal lesions are those of lymphoid
tissue of terminal small intestine.
(1) Hyperplasia Stage ( Peyer’s patches)
(2) Necrosis Stage;
(3) Ulceration Stage;
(4) Healing Stage.
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Hyperplasia stage：
the 1st w after onset
lymphoid tissue swelling protrude out the mucosa ,
looks like cerebral convolution
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Hyperplasia stage
Showing the hyperplasia
of Peyer’s patches of
ileum, which is button-like
elevation
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Hyperplasia stage
looks like
cerebral convolution
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Hyperplasia stage
looks like
cerebral convolution
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Hyperplasia stage
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Microscopy:
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•Necrosis stage： the 2nd w after onset
multi-focal necrosis in lymphoid tissue
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 Ulceration
stage：
the 3rd w after onset，
necrosis tissue fall off and ulcer formation,
longitudinal ulcer is parallel with the axis of
intestinal canal , deep to the muscularis layer
and involve the artery ,which will result in bleeding
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ulceration stage
Key features：
• Round or oval
•Elevated margins
•Uneven bottom
•Parallel to the axis of intestine
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ulceration stage
Key features：
• Round or oval
•Elevated margins
•Uneven bottom
•Parallel to the
axis of intestine
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ulceration stage
ulcer
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Difference
Typhoid fever
Tuberculosis
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Healing stage：
the 4th w after onset
Granulation tissue proliferation ,
scar formation
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Changes in other MPS
Typhoid nodule formation and ulceration in
mesenteric lymph node, the liver, spleen
and marrow.
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Lesions in other organ
Gall bladder: carrier
Heart: slower pulse
Kidney: Albuminuria
Skin: rose rashes
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SYMPTOMS
 Fever (some as high as 40 Degrees)
 Weakness
 Headache
 Loss of Appetite
 Stomach pains
 Rose Rashes
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Complications:
intestinal bleeding
intestinal perforation
lobular pneumonia
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Bacillary Dysentery
Chengcheng You
Dept. of pathology
China Three Gorges University
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Bacillary dysentery is an acute bacterial infection
caused by the genus Shigella resulting in colitis
affecting predominantly the rectosigmoid colon.
The disease is characterized by diarrhea, dysentery,
fever, abdominal pain, and tenesmus.
It is usually limited to a few days.
Mainly occur in infants and young children
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•Pathogen
Shigellae are nonmotile
gram-negative bacilli belonging
to the family Enterobacteriaceae
•Four species:
S. dysenteriae (group A),
S. flexneri (group B),
S. boydii (group C),
S. sonnei (group D).
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Incidence
•most cases of shigellosis occur in children of
developing countries
•S. flexneri is the predominant species
•Children between 1 and 4 years old
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• Infection source： patient and carrier
• route of transmission： fecal-oral route
• Susceptible population:children and young people
• seasonal patterns: autumn and summer
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PATHOGENESIS
•organisms traverse the small bowel, penetrate
colonic epithelial cells and multiply intracellularly
•acute inflammatory response
•pseudomembranous type of colitis
•Epithelial cells containing bacteria are lysed,
resulting in superficial ulcerations and shedding
of shigella organisms into stools
•Diarrhea results because of impaired absorption of
water and electrolytes by the inflamed colon
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Feature

Location:
predominantly the rectosigmoid colon

Clinical type :

Acute bacillary dysentery

Chronic bacillary dysentery

Toxic bacillary dysentery
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Acute bacillary dysentery
Serous inflammation
Mucus secretion increase
diffuse hyperemia
erosion
Fibrinous inflammation
Map-like ulcer
bloody mucoid diarrhea
healing
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Acute bacillary dysentery
•Gross: Affect the colon, producing an acute
inflammation with diffuse hyperemia、
edema and multiple superficial ulcers.
•Pseudomembrane formation: exudate fibrin,
neutrophils, necrotic debris, bacteria
•MI: epithelial cell necrosis, fibrin exudation
monocytes and neutrophils infiltration
abscess formation
•The lesions are often self-limited and can
recover completely
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Pseudomembrane
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pseudomembranous
inflammation
Gross: showing the
pseudomembrane
and irregular ulcers
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bacillary dysentery
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Microscopy:
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Bacillary dysentery
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Complications
•Intestinal Bleeding
•Intestinal Perforation(seldom)
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Clinic Feature

Symptoms begin with sudden onset of high grade
fever, abdominal cramps and watery diarrhoea.

Subsequently diarrhea become mucoid, of small
volume and mixed with blood. This is accompanied
by abdominal pain and tenesmus.

Physical signs are those of dehydration beside
fever, lower abdominal tenderness and normal or
increased bowel sounds.
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Chronic bacillary dysentery
•lasting more than 2 months ,
infected by S.flexneri(福氏菌).
•Clinical features：
Mild symptom of abdominal pain ,diarrhea
Infectious source
•pathological changes：
① chronic ulcers;
② forming polypi ;
③ intestinal wall are fibrosis.
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Toxic bacillary dysentery
Children at the age of 2-7 years old are sensible
most are result from S.sonnei and S.flexneri.
clinical features：
① toxic symptom all over the body:
Toxic shock、respiratory or circulation failure.
② intestinal symptom: mild
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Questions for the class
1.What kind of inflammation is involved in
bacillary dysentery?
2.The definition of typhoid granuloma
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