What Is Tuberculosis
TB is caused by the bacteria Mycobacterium Tuberculosis. It can affect any part of the body but usually infects the lungs. TB is spread through airborne droplets expelled when an infected individual sneezes, talks, or coughs. However, prolonged exposure to the infected individual must occur before an infection is likely to develop.
The body may harbour the bacteria while the immune system prevents sickness. As a result, there are two forms of TB: latent TB and active TB.
With latent TB, the immune system is able to prevent the bacteria from growing. The TB bacteria remain alive within the body but are dormant. However, the bacteria can become active later in life. For instance, if a person’s immune system is compromised or disabled, a TB infection can become activated. Those people with latent TB have no symptoms, do not feel sick, are not contagious, and may develop TB later in life if they do not receive treatment.
Active TB simply means that the TB bacteria are growing within the body causing an active infection. Signs and symptoms of active TB include fatigue, slight fever, chills, night sweats, loss of appetite, unintended weight loss, a cough that lasts three or more weeks producing discoloured or bloody sputum, and pain with coughing or breathing. Active TB is highly contagious.
Clearly, because the TB bacillus becomes airborne when it is expelled from an infected person, poorly ventilated and crowded living conditions accelerate the spread TB. Also, commonly, individuals that live in poverty without access to healthcare advice or resources are most likely not to finish their TB treatment. This can contribute to the emergence of drug resistant forms of TB.
Drug resistant strains of TB are a serious problem. TB bacteria have mutated to develop strains of the bacteria that are resistant to each of the major Tuberculosis medications. There are also strains of TB that are resistant to at least two TB medications. Known as multi-drug resistant TB (MDR-TB), this is posing an ever more deadly threat. Individuals affected with MDR-TB are much more difficult to treat requiring long term therapy of up to two years.
Combination therapies offer the most effective treatment of TB. Also these multiple-drug regimes provide some protection from the risk of drug resistance. The "essential top four" medicines used in various combinations for the treatment of TB are Isoniazid, Rifampicin, Pyrazinamide and Ethambutol.
Summary
Left untreated, each person with active TB disease will infect on average between 10 and 15 people every year.
- Someone in the world is newly infected with TB bacilli every second.
- Overall, one-third of the world's population is currently infected with the TB bacillus.
- Each year, an estimated 8 million to 10 million people contract the disease and 2 to 3 million people die from it.
- The disease kills more young people and adults than any other infectious disease and is the world's biggest killer of women.