How can TB be treated?
All forms of TB are curable if they are diagnosed and treated in time. Treatment involves taking a combination of drugs for six to nine months because some tuberculosis bacteria are naturally resistant to one or more of the drugs prescribed.
The World Health Organisation (WHO) promotes a strategy known as ‘Directly Observed Treatment, Short-course’, or DOTS. This focuses on diagnosis, a standard drug regime, individual monitoring and a secure supply of drugs.
There is now increasing use of community-based approaches for DOTS – nearly 32 million people have been treated using the DOTS strategy since 1993.
Free treatment is often available, but remote communities may not be aware of it. In addition, the cost of travelling to clinics to collect drugs or have treatment supervised can be too much for a family to keep up, and some patients may stop taking their drugs early because relatively they feel better.
The World Health Organisation (WHO) judges TB treatment as one of the most cost-effective health actions available.
What drugs and diagnostics are there?
The test used to diagnose TB is now over 120 years old. It is difficult to use in some places and doesn’t detect all cases of TB, including those in people living with HIV.
A more effective, faster and simpler test is urgently needed.
Similarly, the vaccine used to prevent TB has been around since the 1920s and has only limited effect. Drugs are also old – there have been no new drugs introduced for over 30 years.
How big a problem is drug resistance?
Keeping up a course of treatment can be hard for the poorest and most marginalised. But it is crucial that patients continue treatment for the full period even if they start to feel better. Not finishing the full course of treatment means not all the bacteria may be killed. Resistant bacteria can grow and the disease may come back more deadly than ever. Treating drug resistant TB can take longer, involving more costly drugs and ideally the isolation of the patient.
A growing threat
Multidrug-resistant TB (MDR-TB) is a form of TB that fails to respond to standard first line drugs. Extensive drug-resistant TB (XDR-TB) occurs when resistance to second-line drugs develops on top of multidrug-resistant TB. This type of TB is virtually untreatable.
In 2006, there were an estimated half a million cases of multidrug-resistant TB. There are now around 40,000 cases of extensively drug-resistant TB each year. In 2008, WHO reported the highest rates of multidrug-resistant TB ever recorded.
As well as people stopping treatment courses early because they feel better, resistance is also caused by health workers prescribing the wrong treatment, and because of unreliable drug supplies.
HIV and TB
A third of people living with HIV across the world are thought to be infected with TB, and in Africa the figure reaches two thirds. The increase in TB in recent decades is directly connected to the HIV epidemic, and in countries with high HIV prevalence, the number of new TB cases has tripled in the past 15 years.
People who are HIV-positive and infected with TB bacteria are up to 50 times more likely to develop active TB disease in their lifetime than people who are HIV-negative and infected with TB bacteria.
HIV slowly destroys the immune system, meaning people are less resistant to TB. TB is also harder to diagnose in people living with HIV because they don’t produce sputum in the same way as HIV-negative people. Many of the existing diagnostics for TB aren’t suitable and people die as a result. TB is curable even in a person living with HIV, but new tools and diagnostics are needed urgently.
Isoniazid Preventative Treatment (IPT) is a simple once-daily drug treatment that can prevent active TB in people living with HIV. Taking a six-month course of IPT can reduce the chances of developing TB by 40-60% for two years. IPT is very cheap and could make a real difference but at the moment only 2% of people who need it worldwide have access to it.
Last modified: 16/12/2010
