This document discusses tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis. It spreads through the air and affects the lungs and other organs. Poverty, malnutrition and overcrowding increase the risk. Primary TB occurs via inhaled bacteria forming lesions, while secondary TB results from reactivation of dormant bacteria. Symptoms include cough, fever and weight loss. Diagnosis involves staining samples to identify bacteria and culturing sputum. Treatment requires long-term antibiotic therapy.
3. Tuberculosis
■ Chronic granulomatous inflammation
■ Predominant in developing countries
■ Predisposing factors:
malnutrition,
poverty,
over-crowding,
immunocompromised status
4. Causative organism
■ Mycobacterium tuberculosis (strict aerobe)
■ Tubercle bacillus
■ Also known as Koch’s bacillus
■ Mycobacterium tuberculosis complex-
Eg: M.tuberculosis hominis and M.bovis
Less common strains :
M. africanum
M. microti
M. smegmatis
5. Atypical mycobacteria
■ Also know as non-tuberculous mycobacteria.
■ Or Environmental mycobacteria
1)Rapid growers (within 7 days)
M.abscessus,
M.fortitum,
M.chelonae.
2) Slow growers (2-3 weeks)
■ Photochromogens-yellow pigment produced in light
■ Scotochromogens-pigment produced in light or in dark
■ M.avium intracellulare,M.kansaii etc
■ No person to person contact
10. Pathogenesis
■ Cell mediated immunity and
■ Delayed type of hypersensitivity
Bacterial wall contains the lipids:
A. Mycosides - cord factor of organism
B. Glycolipids - wax D
15. Fate of granuloma
1) Cold abscess
2) Sinus tract formation
3) Coalesce together enlarging the lesion
4) Dystrophic calcification
16. PrimaryTB
■ Ghon’s tuberculosis or childhood tuberculosis
■ Individuals who are not infected previously
■ Lungs and hilar lymph nodes
17. GHON’S FOCUS:
■ A primary lesion usually subpleural
■ Site : junction b/w the upper part of lower lobe and lower part
of upper lobe.
■ It is named for Anton Ghon (1866–1936), anAustrian
pathologist.
■ GHON’S COMPLEX:
GHON’S FOCUS,
HILAR LYMPHNODE INVOLVEMENT
DRAINING LYMPHATICVESSEL INVOLVEMENT
20. Fate of primaryTB
■ Resolution and calcification
■ Progressive primary tuberculosis
■ Primary miliary tuberculosis
21. Secondary tuberculosis
■ Previously infected or sensitized individuals develop secondary
TB
■ Post-primary or re-infection or chronicTB
■ Endogenous source - dormant bacillus
■ Exogenous source - reinfection of bacillus
■ Commonly in lungs
22. Secondary pulmonaryTB
■ Commonest site - Apex of lung
■ Lympho-hematogenous spread
■ HIV patients are more prone
■ M.avium intracellulare occurs in the HIV patients too
23. Fate of secondary lungTB
■ Fibrosis and calcification
■ Tuberculous pneumonia
■ Miliary tuberculosis
■ Empyema
24. FibrocaseousTB
■ Fibrosed tubercle enter bronchus from a cavity -
cavitary or open fibrocaseousTB
■ Non cavitary lesion without entering bronchus -
chronic fibrocaseousTB
32. Intestinal tuberculosis
■ Primary intestinalTB-
Ileocaecal region
Ingestion of M.bovis
Now a days, M.tuberculosis
Mesentric lymph nodes
■ Secondary intestinalTB-
Self swallowing of sputum in active disease
Terminal ileum
37. ■ In the case of primaryTB, tabes mesentrica seen
■ Tabes mesentrica - enlarged mesentric lymph nodes
■ Mesentric lymphatic nodes rupture to causeTB
peritonitis
40. Clinical features ofTB
■ Productive cough may be with hemoptysis
■ Dyspnoea, orthopnea
■ Fever
■ Night sweats
■ Fatigue
■ Loss of weight
■ Loss of appetite
41. Diagnosis
■ Clinical features are not confirmatory.
■ Zeil Neelson Stain
■ Adenosine deaminase test
■ Culture most sensitive and specific test.
– Conventional Lowenstein Jensen media 3-6 wks.
– Automated techniques within 9-16 days
■ PCR is available, but should only be
performed by experienced laboratories
■ Mantoux test
42. Demonstration of organism
■ Ziehl-neelsen staining or acid fast staining
■ Fluorescent dyes - auromine and rhodamine
■ LJ medium for sputum
■ Bactec culture, HPLC(high pressure liquid
chromatography)
■ Guinea pig inoculation
■ PCR
46. Mantoux test
■ Tuberculin skin test
■ 0.1 ml of tuberculoprotein,purified protein derivative
is administered intradermally
■ Induration more than 15 mm in 72 hours
■ DisseminatedTB-negative
■ False positive - atypical mycobacteria,
previous BCG vaccination
■ False negative - sarcoidosis,
recentTB,
hodgkins disease.