In 2009, 9,040 cases of TB were reported in the UK. Most of these occurred in urban centres, with over one-third of cases in London. Globally, TB remains a major public health problem. There were 9.4 million new cases of TB in 2009, and 1.7 million deaths from the condition.
Countries with high numbers of HIV cases also often have high numbers of TB cases. This is because HIV weakens a person’s immune system, which means they are more likely to develop a TB infection.
Tuberculosis will not cause any symptoms until the infection has reached the lungs. As the bacteria are very slow moving, the condition develops very slowly. The symptoms might not begin until many years after initially exposed to the bacteria.
A TB infection of the lungs is known as pulmonary TB. The symptoms of pulmonary TB include a persistent cough that brings up thick phlegm, which may be bloody. A mild breathlessness to begin with then gradually gets worse; weight loss; lack of appetite. A sense of feeling unwell; extreme tiredness.
In some cases, a TB infection can spread from the lungs to other parts of the body. TB infections that occur outside the lungs are known as extra pulmonary TB. This is more common in people with weakened immune systems. A TB infection can spread to; lymph nodes that are near the lungs, bones and joints, the digestive system, the bladder and reproductive system, the nervous system.
When a person is infected with TB different things can happen; their immune system kills the bacteria and they have no further symptoms. This happens in most cases. Or their immune system can’t kill the bacteria, but manages to build a defensive barrier around the infection. This means that they will not have any symptoms, but the bacteria will remain in the body. This is known as latent TB. Or their immune system fails to kill or contain the infection and it slowly spreads to their lungs. This is known as active TB. Latent TB could develop into an active TB infection at a later date, particularly if the immune system becomes weakened.
Both latent TB infection and active TB disease are treated with antibiotics. Treatment lasts at least six months because antibiotics work only when the bacteria are actively dividing, and the bacteria that cause TB grow very slowly. While latent TB infection can be treated with only one antibiotic, active TB disease is treated with several antibiotics at one time, to decrease the chances that the bacteria will evolve resistance to the drugs. Active TB disease must be treated aggressively and patients may have to start treatment with a hospital stay, to keep them from spreading the disease.
The biggest danger in TB treatment is that the patient will not take antibiotics on schedule. This gives the bacteria the opportunity to develop resistance to the drugs, rebound, and become much more difficult to treat. This is because forgetting to take medication, can lead to the life-threatening condition of multidrug-resistant TB. Treat MDR-TB requires long hospital stays and high doses of antibiotics.
Treatment for latent TB infection is usually a single antibiotic for nice months. The goal of this treatment is to eliminate the bacteria from your body. A long treatment is required because antibiotics work only when the bacteria are actively dividing, and the bacteria that cause TB can rest without growing for long periods. This treatment is necessary to keep the latent TB infection form developing into active disease.
Like most bacteria, mycobacterium tuberculosis can develop a resistance to antibiotics. Antibiotic resistance means that the medicines can no longer kill the bacteria they are meant to fight. Tuberculosis that develops a resistance to one type of antibiotic is not usually a concern because alternative antibiotics are available.
However in an increasing number of cases, TB develops a resistance to two antibiotics, this is known as extensive multi-drug resistance tuberculosis. TB also develops a resistance to three or more antibiotics; this is known as extensive multi-drug resistance tuberculosis.
