What you should know about TB

Many people carry the TB bacteria, but not all of them end up developing the disease. A compromised immune system is what makes the difference

It is estimated that about one third of the world population, that is about two billion people, carries the tuberculosis (TB) bacteria.

Out of these two billion people, about 9 million of them get the active disease and as a result, about two million die annually.

The biggest burden of TB is in the low income countries. Kenya is ranked number 13 of the 22 countries with the highest TB burden in the world.

These 22 countries account for about 80 per cent of the world TB cases.

The TB burden in Kenya has grown since the 1990s with the advent of HIV as well as due to increased poverty. In 1990 there were 11,625 reported cases of TB.

These increased tenfold to a peak of 116,723 cases reported in 2007. However the numbers have begun going down, with 106,083 cases reported in 2010.

But despite Government interventions in trying to control the disease, there is an emerging risk of TB bacteria that are resistant to current medical treatment.

Here are some of the common concerns regarding TB:

What is TB?

It is a disease caused by a bacteria called mycobacterium tuberculosis. This bacteria is unique in that it grows very slowly and also dies very slowly during treatment.

The bacteria can affect any part of the body, but it mainly affects the lungs. TB spreads when a person with the disease coughs and the bacteria is spread through the air.

If I inhale the TB bacteria does that mean I will catch the disease?

Not necessarily. Many people who inhale the TB bacteria will get infected, in the sense that the TB bacteria will get to the lungs and the body is able to fight it and make it inactive — the bacteria does not die, it is just subdued.

In most people, the bacteria remains in the lungs in an inactive state for the rest of their lives. However, in others, the bacteria can become active and begin to multiply and spread.

This is what causes the symptoms of TB, which include weight loss, coughing and general malaise.

What leads to the development of TB?

The most common cause that has been HIV, which weakens the immune system, making the body unable to keep the bacteria suppressed and inactive in the lungs.

The TB then becomes active and spreads. Other causes of the disease include diabetes and use of medication that suppresses the immunity.