Pulmonary tuberculosis

DR. Yousef Noaimat MD.FCCPConsultant in pulmonary and

internal medicine.

History

• Tubercular decay has been found in the spines of Egyptian mummies.

• Pictured: Egyptian mummy in the British Museum

Epidemiology

• According to the World Health Organization (WHO), nearly 2 billion people—one third of the world's population—have been exposed to the tuberculosis pathogen

• Annually, 8 million people become ill with tuberculosis, and 2 million people die from the disease worldwide

• World TB incidence. Cases per 100,000; Red => 300, orange = 200–300, yellow = 100–200, green = 50–100, blue =< 50 and grey = n/a. Data from WHO, 2006

Reason for increase incidence

• HIV infections and the neglect of TB control programs

• drug-resistant : from 2000 to 2004, 20% of TB cases being resistant to standard treatments and 2% resistant to second-line drugs

• Lack of access to health care

• Poverty

• Definition :Pulmonary tuberculosis (TB) is a contagious bacterial infection that mainly involves the lungs, but may spread to other organs caused by the Mycobacterium tuberculosis and Mycobacterium bovis

• In the United States, most people will recover from primary TB infection without further evidence of the disease. The infection may stay non active for years and then reactivate.

• Most people who develop symptoms of a TB infection first became infected in the past. However, in some cases, the disease may become active within weeks after the primary infection

Transmission

• cough, sneeze, speak, they expel infectious aerosol droplets 0.5 to 5 µm in diameter. A single sneeze can release up to 40,000 droplets.Each one of these droplets may transmit the disease, since the infectious dose of tuberculosis is very low and the inhalation of just a single bacterium can cause a new infection

• Transmission can only occur from people with active — not latent 

• When the disease becomes active, 75% of the cases are pulmonary TB

• the other 25% of active cases, the infection moves from the lungs, causing other kinds of TB

Clinical presentation

The primary stage of the disease usually doesn't have symptoms. When symptoms do occur, they may include:

• Cough heamoptysis• Excessive sweating, especially at night • Fatigue • Fever • Unintentional weight loss Other symptoms that may occur with this disease:• Breathing difficulty • Chest pain • Wheezing

Examination

• Examination may show:

• Clubbing of the fingers or toes (in people with advanced disease)

• Enlarged or tender lymph nodes in the neck or other areas

• Fluid around a lung

• Unusual breath sounds (crackles)

Diagnosis • Sputum examination and cultures (ZN STAIN)

how can I take a good sample?

• Chest x-ray • Chest CT scan• Bronchoscopy• tuberculin skin test • Gastric aspiration?• The main problem with tuberculosis diagnosis is the difficulty in

culturing this slow-growing organism in the laboratory (it may take 4 to 12 weeks for blood or sputum culture

Mantoux tuberculin skin test

• polymerase chain reaction detection of bacterial DNA, and assays to detect the release of interferon gamma in response to mycobacterial proteins such as ESAT These are not affected by immunization or environmental mycobacteria, so generate fewer false positive results

Treatment

• Latent TB treatment usually uses a single antibiotic • People with latent infections are treated to prevent them

from progressing to active TB disease later in life. However, treatment using Rifampicin and Pyrazinamide is not risk-free. The Centers for Disease Control and Prevention (CDC) notified healthcare professionals of revised recommendations against the use of rifampin plus pyrazinamide for treatment of latent tuberculosis infection, due to high rates of hospitalization and death from liver injury associated with the combined use of these drugs

Treatment

• while active TB disease is best treated with combinations of several antibiotics, to reduce the risk of the bacteria developing antibiotic resistance

• The two antibiotics most commonly used are rifampicin and isoniazid

Treatment

• Initial phase 8 WKS:

• rifampicin +isoniazid +PYRAZINAMIDE

• If resistant possible add ethmbutol or sterptomycin

• Give pyridoxine throughout treatment

• Continuation phase (4month)

• rifampicin +isoniazid+ pyridoxine

Treatment

When can I say treatment failure?

• Treatment failure is defined by

• + culture after 3 months

• +AFB stain after 5 months

• And should be treated by adding 2 more drug

Treatment

• Main side effect

• Rifampicin: hepatitis (small raise of ASTis acceptable . Stop if biliurubin raise)

• Isoniazid: hepatitis. Neuropathy

• ethmbutol: optic neuropathy

• PYRAZINAMIDE: hepatitis

(contraindicted in gout)

Prevention

• identified people with TB and their contacts are and then treated

• children are vaccinated to protect them from TB. Unfortunately, no vaccine is available that provides reliable protection for adults

Thank you