Lungnet

What is Tuberculosis?

Tuberculosis or TB is an illness caused by a germ called "mycobacterium tuberculosis".

The lung is the organ most commonly infected. The germ may occasionally infect the kidneys, bones and joints, lymph glands and many other parts of the body.

How do you catch it?

TB is mostly caught by breathing in the tiny drops coughed up or sneezed by a person who has TB. These drops are invisible and may contain TB germs. Once inhaled, the germs invade the lungs and slowly multiply. At this stage the body's own defences may fight off the infection. This often happens during childhood. TB infection at this time of life may result in no more than mild "flu" like illness. The germ may then cause no trouble for many years. It may become active later in adult life. Only very occasionally does the germ beat the body's natural defences on its first contact and go on to infect other body organs.

Who gets it?

About 800 new cases of TB are found and treated in Australia each year. Newly arrived immigrants and refugees who caught the infection prior to arrival in Australia are at risk. TB is also more likely to occur in people who have low resistance to infection, who are poorly fed, have severe illness or who drinks too much alcohol. The infection can also be caught and controlled by the body's defences only to recur many years later when those defences are weakened by the above problems. The TB germ can also occasionally infect people who are otherwise in good health.

What are the symptoms?

The symptoms of TB include fever, cough, loss of energy and being tired. There may also be sweats, particularly at night, and weight loss can also occur. The cough may produce phlegm and sometimes blood. TB is usually first suspected when changes are seen on a chest x-ray.

How is it diagnosed?

TB can only be diagnosed with certainty if the TB germ is found in a body fluid or organ eg. in the phlegm or urine or in tissue such as lymph glands removed at surgery. Finding the germ allows the laboratory to do tests to find out which drugs will be most effective in treating the TB germ.

A Mantoux skin test is sometimes used in diagnosis. This simple test involves an injection into the skin of the forearm. The test needs to be looked at after 48-72 hours for redness or swelling. These signs indicate past or present TB infection. A very strong reaction should be treated seriously. No reaction can still mean TB germs are in the body in some cases.

How is it treated?

TB is treated with 3 or 4 antibiotics taken together. Unlike other infections which often only need a week or so of antibiotics, TB requires many months of continued treatment to be certain of a cure. The exact length of time varies and depends on many factors. Your doctor will advise you about this. Stopping or not taking the medicine can allow resistant TB germs to develop. These can be much more difficult or even impossible to cure. Properly taken TB treatment now assures an almost 100% cure rate.

People who take TB drugs need regular follow up. Side effects of TB drugs occur occasionally. They are usually temporary. Your doctor will want to keep you under close supervision especially during the first few weeks of treatment. Blood tests or x-rays may be needed at times during these visits. On Rifampicin treatment, urine and tears will temporarily turn a deep orange-red colour. This drug may also make the oral contraceptive pill ineffective.

Is it infectious?

Only those TB patients who have germs in the phlegm or have a weeping infected sore or wound are likely to infect others. This is called 'Open TB". During this infectious period care should be taken to cough into a tissue or a bowl with a cover so that the phlegm can be destroyed. Many other people with TB have the germ deep in the body but do not cough it out. This is called "closed TB". These people are not a hazard to family or friends.

Treated patients mostly become non-infectious within a few weeks. After this time no special hazard is posed to family, friends or contacts.

Government rules

After diagnosis of TB is made it is a legal requirement for the doctor to notify the Department of Health. They will arrange for skin tests and chest x-rays of close contacts. These tests may identify the other people to whom the TB has already been passed.

Please Note: This information is intended by The Australian Lung Foundation to be used as a guide only and is not an authoritative statement. Please consult your family doctor or specialist respiratory physician if you have further questions relating to the information provided here.

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