Tuberculosis is a communicable chronic granulomatous disease caused by Mycobacterium tuberculosis , where the center of the granuloma is Caseous necrosis It usually involves the lungs but may affect any organ or tissue in the body Airborne spread of droplet nuclei

1. Amjad Khan Afridi
Lecturer,
Department of Health & Biological Sciences
Abasyn University Peshawar
Chapter # 07
Tuberculosis

2.  Tuberculosis is a communicable chronic
granulomatous disease caused by
Mycobacterium tuberculosis , where the
center of the granuloma is Caseous
necrosis
 It usually involves the lungs but may
affect any organ or tissue in the body
 Airborne spread of droplet nuclei
Caseating granulomata

3. o Among medically and economically deprived
persons throughout the world, tuberculosis
remains a leading cause of death.
o It is the most common cause of death from a
single infectious agent.
o It is estimated that 1.7 billion people are infected
worldwide, with 8 to 10 million new cases and 3
million deaths per year.

4. since 1985 , In Western World , Death from TB
increased because of increase incidence of
Tuberculosis in HIV- infected persons.

5. Mycobacterium Tuberculosis
• Small, rod-shaped, non-capsulated, non-
spore forming, thin strictly aerobic
bacterium .
• The rods are 2-4 micrometers in length and
0.2-0.5 um in width
• Neutral on gram staining
• Acid-fast bacilli (once stained, cannot be
decolorized by acid alcohol)
• Acid fastness is due to the organisms high
content of mycolic acid
• Like other mycobacteria, it is slow
growing, resulting in more gradual
development of disease when compared
with other bacterial infections.

6. Tb risk factors :-
• AIDS , Immunosuppression
• Drug resistance
• Alcoholism
• Malnutrition
• Chronic renal failure
• Chronic lung disease
• HIV
• Diabetes mellitus
• Cancer

7. Transmission
Although other routes may be involved , but
most infections are acquired by Respiratory
Transmission by :
• Coughing
• Sneezing
• Talking
• Spit
• Laughing

8. Optimal conditions for transmission
include:
• Overcrowding
• Poor personal hygiene
• Poor public hygiene
• Poor nutrition

9. Etiology
• Mycobacteria are slender rods that are acid-fast
• M. tuberculosis hominis is responsible for most cases of
tuberculosis; the reservoir of infection typically is found
in persons with active pulmonary disease
• Oropharyngeal and intestinal tuberculosis contracted by
drinking milk contaminated with Mycobacterium bovis
• Mycobacterium avium complex are much less virulent ,
rarely cause disease in immunocompetent , however in
patients with AIDS , these strains cause disease in 10% to
30%

10. Mycobacterium tuberculosis complex
M. tuberculosis: Human TB
M. caprae: Goat
M. bovix: cattle and other mammals
M. microti: Voles and other small animals/ not human
M. africanum: Africa in btw Human and bovine types

11. Pathogenesis of Mycobacterium tuberculosis

12. Pathogenesis of Mycobacterium tuberculosis
Pathogenesis of TBM and postulation of the formation of Rich
foci.
(a) Aerosol transmission of MTB,
(b) Phagocytosis of MTB by alveolar macrophages inside alveoli.
(c) Granuloma formation in the lung, which subsequently
occurs due to cellular and cytokine network responses; 90%
of hosts with granulomas maintain them stably over the
course of their lives.
(d) MTB escapes from the granuloma, which occurs in 10% of
latent TB patients.

13. Pathogenesis of Mycobacterium tuberculosis
(a) MTB escapes from the granuloma, which occurs in 10% of
latent TB patients.
(b) MTB can cause TBM by escalating from the lung or by
secondary reactivation from a “leaked granuloma”, which is
then filtered into a regional lymph node.
(c) After spreading through the blood circulation, MTB can
enter the CNS through the BBB (blood–brain barrier), likely by a
Trojan horse mechanism.
(d) Bacilli seed to the meninges or the brain parenchyma,
forming subpial or sub-ependymal primary complexes,

14. Signs & Symptoms
• Early symptoms
Common cold symptoms
Fatigue, fever, a minimally productive cough
of yellow or green sputum and a general
feeling of malaise.
• Later symptoms
Night sweats, fever, cough with purulent
secretions and haemoptysis, dyspnoea, chest
pain, and hoarseness.

15. Types of TB infection:
1. Primary TB :Infection in unsensitized or
immunocompromised host
2. Secondary ( reactivation TB)
3. Progressive pulmonary TB
4. Miliary TB
5. Isolated organ TB

16. Primary Tuberculosis
 Is the form of Disease that
develops in a previously
unexposed.
 Formation of lung lesion called
Ghon focus.
 It is commonly found in the sub-
pleural area.
 It drains into the hilar lymph
nodes.
 The combination of the Ghon focus
and hilar lymph nodes is called as
Ghon complex.
 Which lead to caused caseous

17. PRIMARY TUBERCULOSIS: Ghon
Focus & Ghon complex
 Ghon Focus: lung lesion of primary TB, involves upper segments of the
lower lobes or lower segment of the upper lobe.
 Ghon complex: combination of a peripheral ghon focus and involved
mediastinal or hilar lymphnode.
 Microscopically the classic lesion of TB is a caseous granuloma

18. Caseating granulomas

19. Primary
infection
Healed TB
Progressive
TB
Latent TB
Secondary
TB
Primary
TB
Miliary
TB

20. SECONDARY TUBERCULOSIS
It is post primary infection in an
immunized individual.
The mycobacteria in secondary TB may
be either coming
from:
1. Caused by reactivation of dormant
organisms from old granulomas
(dormant primary lesion).
2. This is more common.
3. Factors: Various conditions including
cancer, chemotherapy, AIDS and old
age predispose to endogenous
dormant M. Tuberculosis.

21. Miliary Tuberculosis:
• when bacteria in the lungs
enters the pulmonary venous
return to the heart; the
organisms subsequently
disseminate through the
systemic arterial system and the
lymphatic channels
Systemic miliary
tuberculosis
• It produces multiple small
yellow nodular lesions in
several organs. Almost every
organ in the body may be
seeded. Lesions resemble
those in the lung.

22. Miliary TB
 Millet like – grain.
 Low immunity
 blood or bronchial spread

23. TB adrenal gland
TB epididymis

24. Tuberculoma
Renal TB
TB Vertebra
(Potts
Spine)

25. Lab Diagnosis
• Specimen
• Microscopy
• Culture
• Nucleic acid
• Drug susceptibility test

28. Prevention
• Isolation
• Ventilate the room
• Cover the mouth
• Wear mask
• Finished entire course of medication
• Vaccinations

29. TREATMENT
• Conventional antitubercular therapy for at least 6
months including initial 2 months of HREZ (e.g.
isoniazid, rifampicin, ethambutol and pyrazinamide)
followed by 4 month HR is recommended in all patients
with abdominal tuberculosis

30. Treatment
• DOTS ( Direct Observed Treatment Strategy)
o Treatment partner

32. 20th April, 2022