Tuberculosis (TB)

Causes of tuberculosis

Mycobacterium tuberculosis is the bacteria that causes TB. It is spread through microscopic airborne droplets when a person with active TB sneezes, coughs, spits or laughs. It can present in two forms:

• Latent or inactive — an infection which yields no symptoms, doesn’t make you sick and is not contagious, but may still require treatment to prevent the TB from activating.
• Active — an infectious disease which can easily spread to others and be fatal if not treated properly.

Risk factors for tuberculosis

Risk factors for tuberculosis include:

• Travel — some countries in Africa, Asia, Eastern Europe and Latin America have higher rates of tuberculosis, which means traveling to these countries increases your risk of tuberculosis.
• Occupation — those who work in health care settings are more likely to be exposed to TB.
• Weakened immune system — your immune system is usually strong enough to fight off tuberculosis bacteria, but diseases and medications that weaken your immune system might make it more difficult to prevent TB.

Symptoms of tuberculosis

Symptoms or signs of active tuberculosis include:

• Cough, lasting longer than three weeks
• Fatigue or weakness
• Coughing up blood or phlegm
• Fever
• Chest pain when coughing or breathing
• Chills or sweats
• Loss of appetite

Diagnosis of tuberculosis

Tuberculosis can be diagnosed by a primary care doctor who will ask about your symptoms and listen to your lungs through a stethoscope.

If TB is suspected, they will perform a purified protein derivative (PPD) skin test, in which a solution is injected under the skin and re-examined 24-48 hours later. If you have a raised red bump, you could have TB. How large the bump is determines how severe the case is. Although the skin test is the most commonly used test, results can be inaccurate.

Other diagnostic tests include:

• Blood tests — after drawing blood, a laboratory can identify the presence of tuberculosis bacteria.
• Imaging tests — after a positive skin or blood test, your doctor may recommend a chest x-ray or CT scan to look for white spots in your lungs.
• Sputum test — if a chest x-ray shows TB, your doctor could take a lung fluid sample to check for the presence of the tuberculosis bacteria.

Treatments for tuberculosis

Active tuberculosis requires an aggressive medication treatment, especially as strains of tuberculosis are becoming more resistant to drugs. You will be prescribed a high-dose antibiotic for at least six months and may take this in combination with other antibiotic medication to fight the tuberculosis infection.

Latent TB may require a reduced regimen of the tuberculosis antibiotic treatment, especially for those who have a weakened immune system and may not be able to fight off the infection if it becomes active.

TB treatment is often coordinated with your primary care doctor and a pulmonary lung specialist.

Recovery from tuberculosis

Antibiotic treatments for tuberculosis usually last 6-9 months and should be taken regularly as prescribed and completed entirely, even after you start to feel better.

In most cases, you’re no longer contagious after 2-3 weeks of antibiotic treatment.