tuberculosis pathogenesis
DESCRIPTION
Clinical presentation of active TB Differential diagnosis of TB Etiology Transmission Factors influencing transmission Pathogenesis of Latent TB Disease Co-pathogenesisTRANSCRIPT
Lung TuberculosisDr Hemanth S Naik
24th March 2014
At the end of this presentation, participants will be able to:
Learning Objectives
•Describe the causative agent of Pulmonary Tuberculosis (TB)
•Transmission of TB•Factors influencing the transmission of TB
•Pathogenesis of Latent TB•Pathogenesis of Active TB
•Persistent cough of more than 3 weeks•Associated with green, yellow, or bloody sputum
•Breathlessness•High temperature of 38ºC (100.4ºF) or above
•Loss of weight•Lack of appetite
•Chest Pain•Fatigue
Complaints
Chronic Cough
Common
Upper Airway Cough Syndrom
Chronic Bronchitis
GORD
Pneumonia
Asthma
Etc
Uncommon
Lung Cancer
Bronchiolitis
TB
Etc
DifferentialDiagnosis
Fever
Common
Upper Airway Cough Syndrom
Chronic Bronchitis
GORD
Pneumonia
Asthma
Etc
Uncommon
Lung Cancer
Bronchiolitis
TB
Etc
Weight Loss
Common
Upper Airway Cough Syndrom
Chronic Bronchitis
GORD
Pneumonia
Asthma
Etc
Uncommon
Lung Cancer
Bronchiolitis
TB
Etc
X ray
DefinitionInfectious disease caused by Myobacterium Tuberculosis
M tuberculosis becomes dormant before it progresses to active TB
Most commonly involves the lungs and is communicable in this form
Epidemiology
Transmission
Active TB Patient Healthy Individual
Transmission
Active TB Patient Healthy Individual
Susceptibility
Environment
Infectiousness
Exposure
Factors
Transmission
Active TB Patient Healthy Individual
Increased Chances of Infection
Concentration of TB bacteria circulating in
the air is greater
IndoorsPoor VentilationPoor Sunlight
Greater the time spent with the infectious
person
Transmission
Active TB Patient Healthy Individual
Sharing Food Sharing Cloths Sharing Gadgets
TB Germs Cannot be Spread By
Within 2 to 8 weeks, special immune cells called macrophages ingest and surround the tubercle bacilli.
The cells form a barrier shell, called a granuloma, that keeps the bacilli contained and under control (LTBI).
Latent Tuberculosis
GRANULOMA
If the immune system cannot keep the tubercle bacilli under control, the bacilli begin to multiply rapidly (TB disease).
Active Tuberculosis
GRANULOMA
HIV-infected persons
Recent TB infection
Age (very young or very old)
Injection drug users
LTBTB
TransmissionExposure
No Infection (70%) Infection(30%)
Containment
(95%)
Early Progressio
n(5%)
Continued
Containmen
t(95%)
Late Progression(10%)
Immune Defense
Immune Defense
Immune Defense
TransmissionTrue or False
•M. Tuberculosis is an anaerobic bacteria
•Tuberculosis can be spread person to person by sharing the same cup or bottle
•Persons with LTBI and HIV have a 10% lifetime risk of progressing to active TB disease
•Approximately 25% (1/4) of close contacts to a sputum smear-positive case will have LTBI
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