the most contagious and world emergency disease -tuberculosis

1. BY
Nakka Varshitha
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2. CONTENTS
• Causative organism
• History
• Morphology
• Physiology
• Culture
• Pathogenesis
• Resistance
• Epidemiology
• Mode of transmission
• Signs and symptoms
• Diagnosis
• Prophylaxis
• Treatment
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3. Tubercle bacillus or Koch’s bacillus called” Mycobacterium tuberculosis”
is responsible for causing tuberculosis in lungs and other tissues of the
human body.
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4. HISTORY
 In 1884 Robert Koch isolated the mammalian Tubercle bacilli and
Established its causative role in tuberculosis.
 After the discovery of mammalian type ,other
types were discovered
Avian type – M.avium(1890)
Bovian type – M.bovis(1898)
Cold blooded type – M.marinum(1926)
Marine type – M.microti(1937)
 Lemann and Neumann was given the name
“Mycobacterium” to this genus.
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5.  Slender ,straight or slightly curved
 Acid-fast bacilli
 Non motile,non spore forming
 Aerobic
 Non-capsulated
 1-4cm long and 0.3-0.6cm wide
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6.  Obligate aerobes
 Optimum temperature - 37°c
 Optimum pH - 6.8
 Resistant to detergent and disinfectant.
 They cannot be stained by gram’s method , if stained they appear as gram
positive.
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7.  Tuberculosis is one of the oldest killer
disease of mankind
 About 1/3rd of the world population
was infected with TB
 About 9million new cases of
tuberculosis and 3.5million deaths
occur due to this disease
 In India about 1.5million new cases are
detected every year
 Tuberculosis has been declared as
” Global emergency” by WHO.
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8.  Both solid and liquid media is available for
culture of M.tuberculosis
 Commonly used media is Lowenstein-Jensen
medium
 They grow as mass of cells.
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9.  LJ medium contains :
Hen’s egg
Mineral salt solution
Asparagine
Malachite green
Glycerol or sodium pyruvate
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10.  The media must be incubated for a
significant length of time.
 Colonies usually appear in 2-3 weeks.
 Doubling time of M .bacterium is slow
 Hence Incubation period is up to 6 weeks
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11. Droplet nuclei containing tubercle bacilli are inhaled through
coughing,sneezing,speaking by an open case of tuberculosis
Tubercle bacilli enters the lungs and reaches the aveoli
These Bacilli was ingested by alveolar macrophages and majority of these are
destroyed but macrophages fail to destroy some of them which leads to
multiplication of bacillus inside the macrophages.
.
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12. Macrophages,T-cell,B-cell and fibroblast aggregate to form granulomas,with
lymphocytes surrounding the infected macrophages
Macrophages in the granulmas are unable to present the antigen to lymphocytes
leads to immune supression
Latent infection is caused by entry of bacteria in to the blood stream.
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13. RESISTANCE
• Survive in dust for several months
• In sputum for 20-30 hrs
• Resist to chemicals,disinfectants
• Remains viable in droplet nucleus for
8-10days where as in culture they
remain viable for 6-8 min at room
temperature
• Resistant to decication
• They can be killed in 15-20min at 60ºc.
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14.  Human beings acquire infection with tubercle bacilli by one of the following route:
 Inhalation
 Ingestion
 Inoculation
 Transplacental route
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15.  A bad cough that last for
3weeks or longer
 Chest pain
 Coughing up blood
 Fatigue
 Weight loss
 No appetite
 Chills
 Fever
 Sweating at night
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16. DIAGNOSIS
Microbiological test:
Ziehl-Neelsen staining
Auramine-Rhodamine staining
Biochemical test:
Niacin test
Aryl sulphate test
Catalase peroxide test
Amidase test
Nitrate reduction test
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17. DIAGNOSIS
 Physical examination:
Blood in the sputum
Weight loss
Night sweats
 Radiography:
Chest X ray
Abrengraph
 Immunological test:
Tuberculin skin test
Mantox skin test
Injecting Mantox skin
test intradermally
After 48-72 hrs
measure the size
of tuberculin
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18.  BCG vaccine:
 It is prepared from a stain of attenuated live bovis , that has lost its
virulence in humans because the living bacilli evolve to make the best use
of available nutrients , they become less adapted to human blood and can
no longer induce disease when introduced in to a human host cell.
 BCG vaccine can prevent tuberculosis for a period of 15 years
 It can be injected intradermally at the insertion of deltoid
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19.  Anti tuberculosis drugs can be used for the treatment of tuberculosis as
they act by inhibiting the development of infectious form.
 Commonly used anti tuberculosis drugs are listed as first and second line
drugs
first line drugs:
 Isoniazid
 Rifampicin
 Pyrazinamide
 Ethamubutol
 streptomycin
second line drugs:
 Kanamycin
 Capreomycin
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20.  Ethinonamide
 Cycloserine
 Ofloxacine
 Ciprofloxacin
 Rifabutin
 Rifapentine new drugs
Directly observed therapy:
 Patient compliance is often low during the course of multiple drug
schedules lasting for long course of treatment
 The trained health care professionals provides the anti tuberculosis drugs
and watch whether the patient swallow every doase.
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