Tuberculosis - Diagnosis, treatment & drug resistant TB

Genexpert Tuberculosis test © Cepheid

Genexpert Tuberculosis test © Cepheid

How do you diagnose Tuberculosis (TB)?

It is very difficult to diagnose Tuberculosis (TB) by a person’s symptoms on their own. This is because some other diseases have the same symptoms as TB.

A diagnosis is usually only certain when there is definite evidence of TB bacteria. Some of the TB tests used for diagnosis look directly for the bacteria. Others such as the chest X-ray look for the effect of the bacteria on the person suspected of having TB. Other tests for diagnosis include the skin test, sputum microscopy, the culture test as well as the new Genexpert test.

Major problems with some of the older tests are the lack of accuracy as well as the time they take.

TB Treatment

TB can usually be cured and more than twenty drugs have been developed for treating TB. Most of the drugs were developed many years ago. There are now beginning to be some new drugs such as bedaquiline and delamanid, but they are mainly used for the treatment of drug resistant TB.

Treatment usually consists of a combination of drugs that must be taken for at least six months. But the treatment will only be successful if the drugs are taken exactly as required for the entire length of time.

The drugs are used in different combinations in different circumstances. For example, the “first line” TB drugs are given to people who have never had treatment before. The "first line" drugs are isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), ethambutol (EMB). The drugs must be taken exactly as prescribed under the supervision of a doctor.

If people have had treatment before they may need to take second line drugs.

Drug resistant Tuberculosis (TB)

If someone has drug resistant TB it means that the bacteria in their body won’t be affected by certain drugs that they are resistant to. The drugs just won’t work. There are two main reasons why people develop it. It can be because the person doesn’t take their drugs properly. It can also be that the bacteria that they are infected with, have come from someone who has already got drug resistant TB. Being drug sensitive is the opposite of being drug resistant.

If someone has drug resistant Tuberculosis then they must change drugs. But usually they mustn’t have just one new drug. They need to have several new drugs and for it to be believed that they will all be effective. Drug susceptibility testing which is available in many countries, and is very important, provides information about which drugs a person is resistant to.

Prevention of Tuberculosis (TB)

A major part of the prevention of TB is to stop the spread of  bacteria from one adult to another. This is done by firstly finding the adults who have Tuberculosis. Then providing them with effective treatment which means that they are no longer infectious, and they will also usually then recover from being sick. There is a vaccine, the BCG vaccine, but it is only used for children as it doesn’t seem to prevent the disease in adults.

TB infection control is also important to prevent people from getting infected in health care facilities.

TB Statistics

The statistics for TB show how there are very different levels of the disease in different parts of the world. Not only national governments, but organisations such as the World Health Organisation (WHO) are making significant efforts to End TB.

The countries known as the high burden countries are those with the highest level of disease. They include India, Indonesia, China and Nigeria.

Page updating

This page was last updated in February 2020.
Author Annabel Kanabus

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