Why TB

One third of the world is reported to be infected.

8.2 million cases were active.

1.2-1.4 million death were reported( World Health Organization. 2013.).

Tuberculosis is more common in developing countries.

Tuberculosis (TB)

37 million lives were saved through diagnosis and treatment between 2000 and 2013.

In 2013 an estimated 480,000 people developed multidrug resistant tuberculosis (MDR-TB).

Tuberculosis is the leading killer of HIV positive people.

What cause it

Mycobacterium tuberculosis complex

It includes:

Mycobacterium tuberculosis

Mycobacterium africanum

Mycobacterium bovis

Mycobacterium microti

M. tuberculosis divides every 15–20 hours

MOTT

M. kansasii, M. simiae and M. marinum

M. Scrofulaceum

M. avium

M. Ulcerans

M. abscessus, M. fortuitum

Microscopy

M. tuberculosis is characterized by caseating granulomas containing Langhans giant cells, which have a "horseshoe" pattern of nuclei.Organisms are identified by their red color on acid-fast staining.

Ziehl-Neelsen staining

• granuloma that provides a protection and enable the bacilli to sustain a long-term persistent infection.

• Protective granulomas are formed by cytokines.

• Granulotomatous lesions are important in both regulating the immune response and minimizing tissue damage.

• T cells help maintain Mycobacterium within the granulomas.

DiagnosisDiagnosis of active tuberculosis depend on

signs of lung disease for more than two weeks .

Abnormal chest x-ray. Multiple sputum samples for smear

culture and PCR. (PPD) test. (QFT) test All tests are initial evaluation for

tuberculosis.

Latent tuberculosis infection (LTBI)

is the presence of M. tuberculosisorganisms without symptoms or radiographic or bacteriologic evidence of TB disease.Approximately 90%–95% of those infected will not progress from LTBI to TB disease (CDC).Diagnosis is made be positive PPD or QFT

Treatmentactive tuberculosis

isoniazidRifampicinPyrazinamideEthambutol

The four drugs are used for the first two months.rifampicin and isoniazid for the last four months.

For latent TB treatment only rifampicin and isoniazid are used both together or one of them.WHO recommend directly observed therapy (DOT), the nurse or health care worker watch the patient while taking the medicine.

Anatomy

where

• Right upper lobe:

• Right middle lobe:

• Left upper lobe

TB granuloma

TB fibrosis of lung

Miliary TB. Multiple tiny nodules scattered throughout both lungs

TB

TB

TB or Not TB?

Lung abscess

Alveolar microlithiasis.

Right heart failure. Well-defined masses seen with the right mid andlower zones. These ‘pseudotumours’ represent encysted pleural fluid

within the horizontal and oblique fissures (arrows).Heart failure

interstitial pneumonitis (UIP) formerly

cryptogenic fibrosing alveolitis.

Kartagener syndrome Triad of featuresSitus inversus (50%).

Nasal polyposis and chronic sinusitis.Bronchiectasis.

Mesothelioma. In this case, there are more extensive lobulatedpleural masses

‘Cannon ball’ metastases

Miliary metastases.

Pneumoconiosis –Multiple small dense bilateralpulmonary nodules.

PneumoconiosisSarcoid.

organising pneumonia.Lymphoma.

Metastatic disease.

Sarcoidosis. Egg shell calcification of both hila

Silicosis. Egg shell calcification of both hila.

Previous varicella pneumonia

Wegner’s granulomatosis. Large cavitating lung lesion

Squamous cell carcinoma

Aspergillomas

Sources and refrencesAbout 35,300,000 results (0.26 seconds)A–Z of Chest RadiologyBy Rakesh R. Misra is a Consultant Radiologist in the Departmentof Radiology at Wycombe Hospital, Buckinghamshire Hospitals UK.WHO site.CDC- USAPresentation prepared by: Dr. Mohamed ElafizGeneral practitioner – Medical commission

March 4,2015