general information on TB
Compiled by Mary Patrick, Health Systems Research Unit, MRC
March 2003

What is Tuberculosis
What is TuberculosisTuberculosis, also known as TB, is a disease spread through the air by a person with tuberculosis of the lung. Small droplets of infected sputum are coughed into the air and breathed in by other people. The symptoms of TB may include a persistent cough of more than 3 weeks feeling weak or sick, weight loss, night sweats, chest pain or coughing up blood.

Scientist estimate that one new TB patient infects about three others before they start their treatment and that those who drop out before they are cured infect ten others before dying or presenting themselves for treatment again (source: TB Annual Report 1997-1998:1).

How to get help if you think you have TB
If you think that you have TB you should contact your nearest clinic or local doctor. At the clinic you will be asked to give a sputum sample to determine if you have TB and may b sent for a chest x-ray. If the results of these tests are positive you will be given medication to take and asked to attend the clinic on a regular basis until you are well.

Who is at risk of gettingTBWho is at risk of getting TB
Anyone can get TB but some people are more at risk than others. People at risk are those who:

  • Share the same breathing space with someone who has TB
  • People who are underweight, or have HIV infection, or are ill with another disease
  • People who are exposed to silica i.e Mineworkers

Why it is important that you take your medication
It is very important that you take the medication until the treatment is complete. Normally people are given medicines for 6-9 months. After the first 48 hours of taking the medicine people feel well, this is because 90% of the TB bacteria are killed by the medicine. It is important that you continue to take the remaining medicine so that last 10% of the TB bacteria are killed. Scientist are aware that the last 10% of the TB bacteria are the most difficult to destroy and this is why the treatment program last for such a long time. If you stop taking the medication after the first month or so you will still have a TB infection even if you feel well.

Developing new drugs for tuberculosis
The World Health Organization (WHO) has estimated that TB notification rates in sub-Saharan Africa are expected to surpass 200 per every 100 000 individuals by the year 2005. The reason for this is that patients do not comply in taking their medication for the full six months. Because of this only 60% of people taking TB drugs are cured. WHO have suggested that the pharmaceutical industry develop a drug regime that would last for 2 months and suggest that the cure rates would increase from 60% to 90%.

It is thought that the combination of a better drug and better detection of new cases of TB would reduce the incidence of TB by 76% in the South African population.
(source Dr Chris Dye. STOP TB-WHO http://www.hopkins-id.edu/tb_rpt/report_02.html)

A history of tuberculosis
Where and when humans first became afflicted with tuberculosis is unknown, but it appears to have existed for several thousands of years. Ancient Hindu texts (3 000 BP) refer to TB as Rogaraj, the king of disease and Rajayakshma, the disease of kings. The first of these names emphasize that this disease was, and in many countries still is, the leading cause of death in human societies. The second name stresses that TB, being an infectious disease, strikes indiscriminately and effects kings as well as ordinary people.3

A German doctor, Robert Koch (1881) first identified, the organism that causes TB in humans. He named the organism Mycobacterium tuberculosis that means 'fungus-bacterium' because of the fungus-like membrane that the bacteria produce when grown on a liquid media.1 The organism that causes tuberculosis in cattle Mycobacterium bovis and other animals, as well as in humans, is very similar and this led to the idea that cattle were the original source of tuberculosis infection in humans. Cattle were first domesticated in the Mediterranean basin approximately 7 000 years ago and the early settlers of this area may have developed tuberculosis from drinking milk or eating infected cattle flesh. Archaeologists have identified skeletal tuberculosis of the spine in prehistoric populations from Egypt, Peru, Canada Germany, Denmark and in Britian.2 4

Types of TB
Nearly two-thirds of the population of South Africa are infected with TB and people areTypes of TB often infected with the TB bacteria without being sick. Only one out of every ten people infected with TB will get sick with the disease, since most people's immune systems can control the bacteria for a lifetime. It is not always clear what causes an infected individual to develop active TB sickness. However, immunity is sometimes weakened by poor nutrition, excessive physical stress, old age, or HIV infection. In these cases, as people's immune systems weaken, TB takes advantage. If untreated, after a long period of suffering, people with TB usually die.

TB of the lungs, or pulmonary TB, is the most common form of the disease, but people also get TB of the spine, heart, kidneys, and other parts of the body. Only those with TB of the lungs can spread the disease to others (Source: National TB Control Programme 1997-1998:3).

Multidrug-resistent TB
Multidrug resistant TB (MDR-TB) can develop when patients do not finish their full course of medication. Sometimes people stop taking their medication because they feel better, or they move away from the area where they first received treatment to a new location. If people stop taking their treatment too soon they will most likely get sick with TB again. Since the TB bacteria in this person's body have already been exposed to TB drugs, the bacteria may well have developed resistance. This means that repeat treatment with the same drugs will not be effective. Often it will be impossible to save this person's life and they will die from multidrug resistant TB. People who develop multidrug resistant TB can spread it easily to other, as easily as regular TB.

CONTACTS:

Dr Martie van der Walt
E-mail: vdwalt@mrc.ac.za

Dr Roxanna Rustomjee
E-mail: roxanna.rustomjee@
mrc.ac.za

Prof Valerie Mizrahi
E-mail: mizrahiv@
pathology.wits.ac.za

Prof. Paul van Helden
E-mail: pvh@sun.ac.za

 

Last updated:
04-Jun-2013

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