Tuberculosis Flashcards
Causative organism in tb
Mycobacterium tuberculosis in humans
Mycobacterium Bovis in animals
What is the mycobacterium tuberculosis complex
Africanum
Bovis
Canetti
Microti
Mycobacterium tb , gram stain positive or negative
Positive
Mycobacterium tb characteristics
Obligate aerobe
Non spore forming
Non motile rod
Mesophile
What makes Mycobacterium tb resistant to detergent and antibacterial
Lipid rich cell wall with mycolic acid which is acid fast and retain acidic stains
Types of tuberculosis disease
Pulmonary TB
extra pulmonary tb
Types of pulmonary tuberculosis disease
Primary disease
secondary disease
Types of extra pulmonary tuberculosis
Lymph nodes tuberculosis
pleural tuberculosis
tuberculosis of upper airways
skeletal tuberculosis
genitourinary tuberculosis
miliary tuberculosis
pericardial tuberculosis
gastrointestinal tuberculosis
tuberculosis meningitis
Continents most affected by tuberculosis
Mainly Africa
Asia
South America
Dance with highest incidence of tuberculosis in 2011
Asia 59% incidence
First country with highest burden of tuberculosis cases
India
Main ways of spread of tuberculosis
Sputum
Cough
Crowded place
Severe symptoms of tuberculosis
Persistent cough
Chest pain
coughing bloody sputum
shortness of breath
Urine discoloration
cloudy and reddish urine
fever with chills
fatigue
Steps In the pathogenesis of tuberculosis
Exposure to organism
inhalation of bacteria
No infection in 50% of cases
Infection in 25 to 50% of cases
Bacteria get to lungs
bacteria enter macrophages
Bacteria multiply in macrophages
Formation of granulomatous lesion -> Caseous necrosis
Bacteria can cease to grow with lesion calcification and can reactivate later
Or
Lesion liquefies and spread to blood,organs and lead to death
Or
Bacteria coughed up in sputum
What is primary pulmonary tuberculosis ( aka ghon’s complex or childhood tb)
Infection of individual never infected or immunized
Characteristics of primary pulmonary tuberculosis
Lesions Are peripheral and accompanied by Hilar which are not always detectable on chest radiography
What is secondary pulmonary tuberculosis (aka post primary , reinfection, chronic tuberculosis. )
Individual has been previously infected or sensitized by the organism
Centage of patients with TB that have extra pulmonary tuberculosis
20%
Which type of patients are at risk of lymph nodes tuberculosis
HIV infected patients
Presentation of lymph nodes tuberculosis
Painless swelling of lymph nodes mostly at cervical and supra clavicle nodes
Organs involved in tuberculosis of upper airways
Larynx and pharynx epiglottis
Sensation of tuberculosis of upper airways
Dysphagia
chronic productive cough
Percentage of genitourinary tuberculosis in all extra pulmonary cases
15%
Symptoms of genital urinary tuberculosis
Urinary frequency
dysuria
hematuria
Symptoms of skeletal tuberculosis
Pain in hip joints and knees
swelling of knees
trauma
Git tuberculosis symptoms
Abdominal pain
diarrhea
weightloss
Generally This Is the only evidence of infection in an asymptomatic individual
Tiny fibrocalcific pulmonary nodule at site of infection
How does the tuberculin PPD or Mantouxskin test work
It detects the mycobacteria tuberculosis antigens 2 to 4 weeks after infection through injection of proteins derivative of mycobacteria tuberculosis
If positive a Palpable induration will peak in 48 to 72 hours
Can you differentiates infection from active disease with the tuberculin skin test
No
Only detect Presence of Tcell mediated immunity to microbacterial antigens
When can you have a false positive tuberculin skin test
BCG vaccine
infection by atypical mYCObacteria
Two types of pathophysiology clinical tuberculosis
Primary - non immune host
Secondary - host immune to M. tuberculosis
Why is it difficult to diagnosis primary tuberculosis
Only 5 % clinically visible and when so , resembles an acute bacterial pneumonia
Primary tuberculosis clinical features
Consolidated lobe
Hilar adenopathy
Pleural effusion
Main part of lungs affected by secondary tuberculosis
Apex of upper lobes of one or both lungs
Clinical features of secondary tuberculosis
Systemic - malaise, anorexia, weight loss, low grade rémittent fever
Pulmonary involvement - sputum (mucoid then purulent), hemoptysis , pleuritic pain
Diagnostic test of tubercle bacilli
Acid fast smear
Sputum culture - solid agar media in 3 to 6 weeks , liquid media in 2 weeks
PCR
I what is military tb
Blood borne dissemination of M tuberculosis
Clinical features of military tb
2-3 weeks of fever, night sweats , anorexia , weight loss , dry cough
Hepatosplenomegaly
How do we check for drug resistance before management
G
