Tuberculosis is an infectious disease usually caused by the bacterium mycobacterium tuberculosis. When it affects the lungs it is known as pulmonary tuberculosis while those that affect other parts of the body like the brain, kidney and spine are known as non-pulmonary tuberculosis.

In 2016, there were more than 10 million cases of active TB which resulted in 1.3 million deaths. This makes it the number one cause of death from an infectious disease. The bacteria that cause tuberculosis are spread from one person to another through tiny droplets released into the air via coughs and sneezes.

Symptoms

Most people infected with tuberculosis do not have symptoms, in which case it is known as latent tuberculosis however, this can progress to the active disease. About 10% of latent infections progress to active disease which, if left untreated, kills about half of those infected.

Latent tuberculosis: In this condition, the bacteria present don’t cause symptoms. The bacteria in the  body is in an inactive state incapable of causing infection but it can turn into active TB. Treatment is important in people with latent TB so as to properly control the disease. It has been discovered that an estimated 2 billion people have latent TB.

Active tuberculosis: In this stage the bacteria is active and can cause disease making it contagious. It can occur in the first few weeks after infection with the TB bacteria, or it might occur years later. Symptoms include:

  • Fever
  • Cough of more than 3 weeks duration
  • Coughing of blood
  • Chest pain or pain with breathing
  • Fatigue
  • Unexplained weight loss
  • Night sweats
  • Loss of appetite
  • Chills

In other cases, symptoms occur based on the part of the body affected. If it affects the kidney blood is seen in the urine, tuberculosis in the spine causes back pain.

Causes

Tuberculosis is caused by mycobacterium tuberculosis which is transferred from an infected person to another through microscopic droplets released into the air. This happens when the untreated person sneezes, coughs, spits, laughs or sings.

Active TB is contagious but you are less likely you contact it from a stranger. a person is more likely to be infected by a person they work or live with. Most people with active tuberculosis who have been appropriately treated for 2 weeks are no longer contagious.

Risk factors

Anyone can get tuberculosis, but certain factors can increase your risk of the disease. These factors include:

  • Weakened immune system due to certain conditions like cancer, malnutrition, diabetes and HIV
  • Infants and children aged less than 4 years
  • People infected within the previous two years
  • People infected with HIV

Diagnosis

For diagnosis to be made, a thorough physical exam and history is taken by the medical personnel coupled with other investigative tests.

  • Skin test: This is done by injecting PPD tuberculin under the fore-arm to check for any swelling under the skin. If the skin swells it shows that there might be a possibility of a TB infection but this test isn’t reliable.
  • Blood test: Blood tests may be used to confirm or rule out latent or active tuberculosis. These TB tests include; Quantiferon-TB Gold in-Tube test and T-Spot.
  • Imaging test: If you’ve had a positive skin test, your doctor is likely to order a chest X-ray or a CT scan. This test reveals abnormal changes in the lungs
  • Sputum test: If your chest X-ray shows signs of tuberculosis, your doctor may take samples of your sputum, the mucus that comes up when you cough. The samples are tested for TB bacteria.

Treatment

The treatment of TB is done by a combination of anti-biotics that must be taken for 6months.  But the treatment will only be successful if the drugs are taken exactly as required for the entire length of time. The drugs are used in different combinations in different circumstances. For example, the five “first line” drugs are given to people who have never had treatment before.

The exact drugs and length of treatment depend on your age, overall health, possible drug resistance, the form of TB (latent or active) and the infection’s location in the body. If you have latent tuberculosis, you may need to take just one type of TB drug. Active tuberculosis, particularly if it’s a drug-resistant strain requires combination of several drugs which is taken effectively at once over a period of 6 months. This common medications used to treat tuberculosis include:

  • Isoniazid
  • Rifampin (Rifadin, Rimactane)
  • Ethambutol (Myambutol)
  • Pyrazinamide
  • Streptomycin

Some of the drugs have very severe side effects and are very difficult to take for such a long period of time. It has also been discovered that some people are already resistant to some of the drugs.

If you have drug-resistant TB, as a result of non-compliance to therapeutic regimen, a combination of antibiotics called fluoroquinolones and injectable medications, such as amikacin, kanamycin or capreomycin, are generally used for 20 to 30 months. If you are resistant to these drugs, a number of new drugs are being looked at as add-on therapy to the current drug-resistant combination treatment. they include;

  • Bedaquiline
  • Linezolid

The side effects of TB medications are common and dangerous. They commonly affect the liver therefore, it is important you take note of the signs and symptoms you experience while taking the drugs. You should carry your doctor along when you notice some odd symptoms. some of the symptoms include; fever, vomiting, dark urine, jaundice. Completing the TB drug therapy is crucial as stopping or skipping the medication doses can allow the bacteria that are still alive to become resistant to those drugs. This leading to TB that is much more dangerous and difficult to treat.

To help people stick with their treatment, a program called directly observed therapy (DOT) is recommended. This improves adherence by requiring health workers, community volunteers or family members to observe and record patients taking each dose of their drugs.