Tuberculosis (Koch's disease) Flashcards
Pulmonary tuberculosis is spread by?
Pulmonary tuberculosis is spread by droplet infection (coughing, sneezing etc) due to Mycobacterium tuberculosis.
is Mycobacterium tuberculosis aerobic or anaerobic
Strict aerobic bacteria
Why mycobacterium described by acid fast bacillus
Described as acidfast bacillius because Has mycolic acid in its cell wall( therefore able to resist decolourisation by a treatment with a mixture of acid and alcohol. during staining )
The reservoir for TB is ?
Human being with active tuberculosis
why M. tuberculosis different disease
Infection with M. tuberculosis is different from disease. Infection is the presence of organisms, which
*
may or may not cause clinically significant disease.
—————is asymptomatic though it may be associated with fever and pleural effusion.
Primary tuberculosis
Infection with M.tuberculosis leads to the developnent of which hypersensitivity? and may be treated with what?
Infection with M. tuberculosis typically leads to the development of delayed hypersensitivity to M. tuberculosis antigens, which can be detected by the tuberculin (Mantoux) test.
A positive tuberculin test reslts signifies of what?
A positive tuberculin test result signifies cell mediated hypersensitivity to tubercular antigens but does not differentiate between infection and disease
which stain is used for acid fast bacilli
Ziehl neelsen stain
The Ziehl neelsen stain is used to identify?
Ziehl neelsen stain is used to identify mycobacteria in a tissuesThese organisms stain as red rods (), seen here at high magnification.
What does large amount of mycolic acids impart
The large amount of mycolic acid imparts this acid-fast property to the mycobacteria and also accounts for their resistance to immune cell destruction.
The destruction of acid-fast bacilli depends upon what?
Their destruction depends upon a subtype 1 helper T-cell (TH1) immune response with CD4 cell elaboration of interferon-γ that recruits monocytes and transforms them into epithelioid macrophages, then stimulates upregulation of nitric oxide synthase within epithelioid cell and giant-cell phagosomes.
What does the PCR does in pulmonary infetions acid-fast bacilli
PCR analysis of respiratory specimens provides greater sensitivity and specificity for detection ofMycobacterium tuberculosisthan microscopy
Name the tuberculosis that develops in a previously unexposed and unsensitized individual
Primary tuberculosis
The sources of primary tuberculosis is usually endogenuous or exogenous?
exogenous
Primary tuberculosis usually develops in the?
Lungs
Most patient with tuberculosis develops latent disease while a minority develops what?
Progressive infection
Typically the inhaled bacilli implant in the ?
distal airspaces of the lower part of the upper lobe or the upper part of the lower lobe due to most of the inspired air being distributed here and form a subpleural lesion.
What is Ghon’s complex
subpleural lesion +draining lymphatics + lymph nodes is called as Ghon’s complex
Histologically apperance or primary tuberculosis
Histologically
The sites of active disease show a characteristic granulomatous inflammatory reaction having the
presence of both caseating and non-caseating tubercles. There is also presence of Langhans giant
cells and lymphocytes
During first few weeks, what is witnessed in the other part of the body?
During the first few weeks, there is also lymphatic and hematogenous dissemination to other parts of the body.
Explain the simon focus
At times, occult hematogenous spread occurs in primary TB where the focus is then called Simon focus
In majority of period which immunity controls infection in the primary tuberculosis
In majority of the people, development of cell-mediated immunity controls the infection
The Ghon’s complex undergoes what?
Progressive fibrosis and calcification
Pattern of disease arises in a previously sensitized host
Secondary tuberculosis
The secondary tuberculosis results to reactivation of what?
Results from a reactivation of latent primary lesions after many years of an initial infection, particularly when host immunity is decreased or uncommonly may follow primary tuberculosis.
Secondaey pulmonary tuberculosis is localised where?
Secondary pulmonary tuberculosis is classically localized to the apex of the upper lobes of the lungs called as Puhl lesion.
explain the difference between right and left lung in secondary infection
The right lung is affected more commonly as compared to left because of high oxygen tension in the apices.
what is assman focus
Infraclavicular lesion of chronic pulmonary TB is called assman focus.
In secondary tuberculosis the preexistance of hypersensitivity controbutes to what?
The preexistence of hypersensitivity contributes to an immediate and marked tissue response leading to localization of the infection (the regional lymph nodes are less prominently involved in secondary tuberculosis) and cavitation followed by erosion into an airway (leading to spread of bacilli during coughing).
Histologically appearance of secondary tuberculosis
Histologically, the active lesions show characteristic coalescent tubercles composed of epithelioid cells and langhans cells with central caseation.
FILL IN THE MISSING WORDS
Progressive ———— tuberculosis
It is seen in the —————— and the immunosuppressed individuals.
The ———–lesion enlarges with increase in the area of ——————–.
The erosion of blood vessels (particularly bronchial arteryQ) results in —————.
The pleural cavity is associated with ——— or ———–.
If the treatment is adequate, the disease may be ———– but if it is inadequate, the infection may ———– through airways, lymphatics or the vascular system
Progressive ** pulmonary** tuberculosis
It is seen in the **elderly ** and the immunosuppressed individuals.
The apical lesion enlarges with increase in the area of caseation.
The erosion of blood vessels (particularly bronchial arteryQ) results in hemoptysis.
The pleural cavity is associated with pleural effusion or empyema.
If the treatment is adequate, the disease may be **controlled **but if it is inadequate, the infection may disseminate through airways, lymphatics or the vascular system
