A Virulent New Form of TB

You'd think the emergence of a fatal disease—especially one that can be spread without physical contact—would be a big story. Yet a threatening new form of tuberculosis called extremely drug-resistant TB, or XDR-TB, has garnered almost no attention. That could soon change, with a new publicity campaign in 50 cities worldwide, centered on a series of dramatic pictures by photographer James Nachtwey and an Internet campaign at xdrtb.org. As the campaign shows, TB is not just an affliction of an earlier era. It still infects millions of people, killing about 1 in 6 of them. In the 1990s, there emerged a scary new version called multi-drug resistant TB (MDR-TB). And now there is XDR, which is even harder to treat.

NEWSWEEK's Anne Underwood spoke with Dr. Mario Raviglione, director of the World Health Organization's Stop TB Department, and Anna Cataldi, world ambassador for WHO's Stop TB Partnership. Cataldi has served in the past as a U.N. messenger of peace for former Secretary General Kofi Annan, and as spokeswoman for UNICEF in Bosnia and Herzegovina. Excerpts:

NEWSWEEK: Why have we heard so little about XDR-TB? When did it emerge?
Anna Cataldi: It emerged several years ago. [The first official reports from the WHO and CDC were published in March 2006.] It didn't get much attention because of all the publicity surrounding avian flu.

How many cases of XDR are there?
Dr. Mario Raviglione: We don't know for sure, because the vast majority of countries have no sophisticated laboratory equipment to detect it. There are nine million cases of TB every year, including half a million cases of MDR. The general estimate is that about 10 percent of MDR cases are actually XDR. We're talking 30,000 to 50,000 cases worldwide in the latest estimate.

Cataldi: Some of the first places where it was found were South Africa, where it is spread by miners who are migrants, and in jails in the former Soviet Union. But now there are cases in more than 40 countries. A few cases have been diagnosed in New York.

How high is the death rate?
Cataldi: In KwaZulu-Natal [South Africa], there is 90 percent mortality. Patients survive one to two months. There are no good drugs to treat it. That's why it's so dangerous. It could become much worse than SARS. If it spreads, it could turn into a deadly pandemic.

Raviglione: But the mortality rate isn't entirely known. In other countries with more aggressive treatment protocols, mortality is more like 50 percent. In Peru, a study in the New England Journal of medicine showed a cure rate of 60 percent. That's the highest anyone has achieved with XDR.

By contrast, the cure rate of normal TB is . . . ?
Raviglione: . . . . 95 percent. It's very curable. You use a cocktail of four drugs for two months, then two of these drugs for another four months. But in some places, doctors will use only one drug, contrary to the standard protocol. That single drug might kill 99.99 percent of TB bacilli [germs] in your body. You will feel better, because you have dramatically decreased the bacilli—but the one bacillus that survives keeps replicating, because it is not susceptible to the drug treatment. Two months later, the person starts deteriorating again, as the surviving bacillus creates a new, drug-resistant population.

So MDR and XDR are caused by poor treatment of the disease?
Cataldi: Also by misdiagnosis and the unwitting use of counterfeit drugs, so that patients are not treated effectively.

How do you treat XDR?
Raviglione: The two strongest drugs [for normal TB] are ineffective against XDR. The remaining two drugs may still work, but these are weak drugs. So you have to turn to the second-line drugs that are used for MDR. Again, the best of these are ineffective against XDR, so you're left with three or four drugs that are not only weak, but also cause toxic side effects.

What kind of side effects?
Raviglione: Gastrointestinal distress—including diarrhea and stomach aches—liver damage and neurological problems such as psychotic reactions and seizures.

Cataldi: I'm not a doctor, but when I spend time with health workers giving these medications to patients, people will say the medicines make them feel worse. They have a tendency to stop the treatment for this reason.

How expensive is XDR to treat?
Raviglione: The drugs used to treat normal TB are very cheap—$20 for six months of treatment in the developing world. The main cost is medical assistance and oversight to make sure that people take their drugs regularly. By contrast, the drugs used to treat MDR can cost up to $20,000 for the two years of treatment that are required.

I ' ve heard scientists argue that highly virulent diseases like Ebola tend to die out because they kill off their hosts before people can spread them around. Is this true of XDR?
Cataldi: No. You can still infect a lot of people in the months you survive. TB is airborne. It's not like HIV, where you need person-to-person contact. With TB, a carrier can just cough or sneeze—even speak—and spread the disease.

According to this campaign, TB has been with us for centuries.
Cataldi: Other diseases have come and gone, like the Black Plague or Spanish Flu. But scientists have found DNA of the TB bacillus in the mummies of high priests in ancient Egypt. A Neolithic skeleton in Germany showed indisputable signs of TB. References to a disease resembling tuberculosis are found in the ancient texts of the Hindu Vedas. Every culture—Chinese, Malaysian, European, American Indian—has had it.

Yo u said earlier that there ' s a problem with misdiagnosis. Don ' t patients have severe coughs and wasting that are easy to detect?
Cataldi: There are many forms of TB. If it's just in the lungs, it's easy to identify using X-rays. But when it spreads beyond the lungs, it is harder to diagnose. It can invade the lymphatic system or bones or liver and kidneys. Scrofula is a form of TB that causes a large bump on the neck. Eleanor Roosevelt died of tuberculosis widely dispersed through her body, although doctors only learned this upon autopsy.

Does the existence of XDR mean we ' ve failed at fighting TB?
Raviglione: It's a sign that things have gone wrong in many places, due to mismanagement of cases, careless prescriptions of drugs, incorrect regimens and the lack of support and follow-up with patients. Together, these problems have created MDR- and XDR-TB. If we do not turn the tide by establishing good, basic TB control and care practices, it will lead to an increase in XDR-TB.

Cataldi: Drug companies are not very interested in TB, because the drugs are so cheap. By contrast, antiretroviral cocktails for HIV are a gigantic business. The drugs we use for TB now are 50 years old. Further dissemination of XDR-TB may stop all progress we've made in recent years in control [of normal TB].

It sounds as if you will be busy as ambassador.
Cataldi: I'm leaving this week for Jordan, where I will visit hospitals, alert people to the problem, meet with the health minister and possibly raise funds, which is very difficult.

It sounds as if you lead an interesting life.
Cataldi: It's tiring. I would like to rest.