Although tuberculosis (TB) can affect almost any part of the body, I have dealt with it in respiratory illness since the lungs are most frequently affected.

TB is an increasingly serious disease world-wide, and is a major public health problem here in South Africa. In South Africa in 1993, before the increase in incidence of HIV, TB was the most commonly reported infectious disease, with a national prevalence of 223 per 100,000 people. The highest incidence is in the Western Cape, with 703 people in every 100,000 infected. By 1993, TB patients comprised 41% of all patients seen by clinics run by the Cape Metropolitan Council.

What is TB, why is it so common here and what can we do about it?

What is TB?

TB is a disease caused by an organism called Mycobacterium tuberculosis. It is a chronic infection, usually of the lungs, called pulmonary, but almost any organ may be affected. In a country such as South Africa where TB is both endemic and epidemic, most people have been exposed to the infection. As a result adults will have a positive skin reaction to TB, called a tuberculin skin test, making this little use in diagnosing the disease, although this is widely used in developed countries.

TB usually occurs in the lungs, where it may be as a result of new infection, or recurrence of infection acquired years ago.

Other parts of the body commonly infected are the spine, the brain - as TB meningitis - the lymphatic system and the gastrointestinal system.

Symptoms of pulmonary TB

In the early stages there may be no symptoms at all. However, as the disease progresses the infected person will complain of tiredness and loss of appetite, cough with sputum production, loss of weight, night sweats and shortness of breath. In advanced TB the person may be emaciated and coughing up blood.

How is pulmonary TB diagnosed?

The usual way to diagnose pulmonary TB is by examining a sputum sample under the microscope, where what are called acid-fast bacilli are seen.

A chest x-ray is usually also taken, although this is not always necessary to the diagnosis. It is of most use in seeing the extent of the disease. In those who have HIV infection the chest X-ray may be normal.

TB in children

TB in children rarely affects the lungs. It is usually either found in the lymphatic system , where it is known as primary TB, or in the gastrointestinal system. If the lungs are affected then it is called progressive disease and is usually a secondary infection.

Diagnosing TB in children is not simple since they do not present with the same type of symptoms as an adult. They may show little other than a failure to gain weight and general malaise.

TB is suspected in a child who has had close contact with an adult with TB, is not gaining weight properly, is not recovering from a respiratory infection or has a perisitent cough or wheeze.

Skin testing is used in children, but does not always provide a definitive diagnosis. A stongly positive tuberculin skin test with a chest X-ray which shows enlarged lymph nodes is regarded as primary TB and treated. A child with a stongly positive skin test with a normal chest X-ray is usually treated with drugs to prevent TB from developing, watched and refered as necessary.

Contact with a person with TB

Because TB is so common in this country many people find themselves in contact with someone who have TB and are understandably worried about catching the disease.

It is important to realise that TB is predominantly a disease of poverty, overcrowding and malnutrition, all of which depress the immune system, making infection more likely. If you are a well-nourished person from a good home, the chance of you catching TB from someone you work with, or from your domestic worker are very small.

It is also important to emphasise that once someone is being treated for TB, even right at the very begining of their treatment, they are not infectious.

If you discover that someone with whom you have daily contact has TB then any local TB clinic will be glad to see you. They will usually offer you a chest X-ray and a visit to the doctor who will be able to talk to you and examine you to see if there is any sign that you may have caught TB.

If your domestic worker has TB and you have children under the age of 2 in the house, then the children will generally be put on a drug to stop them from getting TB, for a period of 3 months.

Treating TB

TB can be cured. However, because of the way in which the organism behaves in the body, the treatment takes a minimum of 6 months. This is because little pockets of infection can remain in the lungs over a period of time, so long-term treatment is required to make sure that all these pockets have been dealt with.

Treatment is usually only for 5 days a week, which gives the body a rest from the drugs which have nasty side effects.

Someone who has not had TB before is first treated with 3 drugs for 2 months, then, as long as their sputum is negative, with 2 drugs for a further 4 months.

If someone has had TB before then they are treated slightly differently, needing a daily injection for the first 2 months, which is stopped once the sputum is negative.

The drugs used are usually rifampicin, INH, pyrazinamide and ehtambutol.

Why is TB such a problem in South Africa?

If TB can be cured, then why does it continue to be such a problem?

There are a number of probable reasons for this.

TB treatment is unpleasant to take with side effects such as nausea. The tablets are large and taste unpleasant, so people are reluctant to take them. As well as this, once you are on treatment you start to feel better, so think that it is no longer necessary to take the tablets at all.

The result of incomplete treatment is either persistent disease, or worse, disease which is resistent to the normal drugs used. This can be fatal.

As a result of this the World Health Organisation (WHO) has introduced a system called directly observed treatment (DOTS), which has actually been used in the Western Cape for decades. This means that someone with TB has to have their daily treatment supervised by a responsible person, or go the local TB clinic every day for treatment.

This leads to problems in itself, since there may not be a responsible person at work or home, and having to go to the clinic every day means time off work, or away from home.

This is why it is so important for employers and others to understand about TB infection and to support people who have the disease through 6 months of very difficult treatment.

This is not the time to dismiss your domestic worker, since she may not be able to get proper treatment elsewhere, and she needs good food which she will not get if she is unemployed. Many clinics will allow an employer to supervise treatment, and encourage people to come into the clinic to learn about the disease.

The other reason why TB persists in areas such as the Cape Flats is poverty, which leads to overcrowding and malnutrition. Until these problems are addressed, we are unlikely to get on top of the problem.

The rise in HIV infection is also contributing to the incidence of TB, since those with HIV have a compromised immune system making them more likely to get the disease.

TB affects all of us in South Africa and those of us in the Western Cape most of all. Learn about the disease, give support to those with it and help erradicate it from our society.