By Richard Skolnik
In 2006, 53 people in South Africa became ill with a form of TB that cannot be cured with the standard TB drugs.
Fifty-two of them died.
Some years before, there was an outbreak of TB in New York City that did not respond to standard TB treatment. These outbreaks should have made us take much greater notice of TB. Unfortunately, however, much work on effectively treating TB remains to be done, as we are reminded by World TB Day and by a new World Health Organization (WHO) Report on drug-resistant forms of TB.
There are about 9.4 million new cases of TB a year and about 1.8 million people a year who die of TB, making it one of the leading causes of adult death in low-income countries.
TB is spread in an “airborne” manner, when people with TB breathe out the TB bacteria and someone else breathes it in. Each person with TB is thought to infect 10 to 15 people per year. “Regular” TB can be cured with a 6-month course of treatment that is not expensive.
However, some forms of TB, like those that occurred in South Africa and New York City that are referred to above, cannot be cured with the regular TB drugs. One such form is resistant to two of the standard drugs and is called “multi-drug resistant” TB” (MDR-TB). Another form of TB is resistant to even more TB drugs and is called “extensively drug-resistant TB” (XDR-TB). People can get drug-resistant forms of TB by not fully taking their drugs when they have TB. People can also get MDR-TB or XDR-TB by breathing in bacteria from people who already have these types of TB.
It is harder to treat MDR-TB because it costs 10 times more to treat than drug-susceptible forms of TB, and the treatment success rates are much lower. It is even harder and even more expensive to treat XDR-TB.
The best way of avoiding the development of more drug-resistant TB in the world is to diagnose people at an early stage of the disease and then to successfully cure them. It is also important to successfully treat the cases of MDR-TB that already exist, so this form of TB cannot be spread further.
The new WHO report on MDR- and XDR-TB provides all the excuses we could want for getting involved with the battle against all forms of TB. The good news is that progress is being made against MDR-TB in some places, such as in the Russian Federation. The bad news, however, is that the data on resistant forms of TB is so limited that WHO cannot tell us the true number of cases worldwide or if that number is going down. Even worse news is that 150,000 people died of MDR-TB in 2008, and there are 440,000 new cases a year globally with only about 1% of them being treated properly. Moreover, there are some regions in Russia in which about 25% of all TB is MDR-TB and 58 countries have now reported XDR-TB.
We need to act urgently to get TB on the top of the global health agenda. We also need to urgently support better detection of TB cases and their successful treatment, everywhere in the world. We must push as hard as we can to get the world to strengthen laboratories for diagnosing MDR-TB. This has to be coupled with measures to encourage the development of new ways of diagnosing all forms of TB, new drugs that can work better and faster on all forms of TB, and the development of a safe and effective TB vaccine. Astoundingly for a disease of such importance, the TB vaccine is not very effective and is more than 100 years old.
We are all at risk for TB and MDR-TB poses special risks because it is harder to diagnose and harder and more expensive to treat successfully
We need to act now because waking up in a world with an increasing number of cases of drug-resistant forms of TB should be a thought too horrible to contemplate.
Richard Skolnik is a half-time Lecturer in Global Health at the George Washington University. He previously served 25 years at the World Bank, two years as Executive Director of the Harvard PEPFAR Program, and two years as Vice-President for International Programs at PRB. He was involved in the establishment of STOP TB and is the author of Essentials of Global Health.