UN Says Drug-Resistant TB Threatens World

by Don Hill

The World Health Organization (WHO) says Russia, the Baltic states, and Central Asia are "global hot spots" for multidrug-resistant tuberculosis, which is threatening to become a worldwide epidemic.

The UN health agency has sounded this alarm before. But in presentations today in Geneva and elsewhere, it raised the volume, saying it has completed an international survey that discloses a heightened and growing danger.

Dr. Paul Nunn, program director for drug-resistant tuberculosis (TB) at the WHO, says, "Well, we've just completed a survey which illustrates that drug-resistant [TB] in the former Soviet Union has become a major, major health problem," he said. "And it's not just the Russian Federation. It's the Baltic states, Central Asia and also parts of China and India."

Nunn says the survey represents one out of every five people in the world. "We've surveyed about 67,000 [TB] patients across the world, and the population we've surveyed represents about one-fifth of the world's population," he said. "It shows us that drug resistance is everywhere and that multidrug resistance -- which is the very serious form of resistance where the two main drugs that we use to treat tuberculosis -- are ineffective. And that, too, is found everywhere. And the levels found in the former Soviet Union are about 10 times that found anywhere else."

He says the WHO places the blame squarely on health authorities in those countries. "And what this tells us is that the systems, the mechanisms, for controlling tuberculosis in these countries are not up to international standards," Nunn said.

In recent years, tuberculosis has risen to epidemic proportions in parts of Eastern Europe, Russia, Central Asia, and Asia. That, in itself, is troubling but not cause for grave concern. A regimen of drugs that cost about $7 to $10 can usually cure an infected patient in a few months.

What is frightening is when the TB virus mutates -- as it is now doing in many places -- into a form that one drug, or even a cocktail of drugs, cannot defeat. When physicians or health authorities use anti-TB drugs improperly, the drugs may kill off the most sensitive viruses, but those tending toward drug resistance survive.

Examples of such ineffective treatments occur when health workers administer less than the proper doses, when drug supplies run out, or when patients share drugs or deliberately cease their treatment. Thus, medical personnel actually breed TB viruses that do not respond to known treatments or require treatment 100 times more expensive than the ordinary regimen.

The WHO says that Estonia, Kazakhstan, Latvia, Lithuania, parts of the Russian Federation, and Uzbekistan -- where up to 14 percent of new patients have strains of the disease resistant to the most powerful drugs -- are among the world's top 10 TB hot spots. Israel, China, Ecuador, and South Africa were also named by the report as countries with a high prevalence of drug-resistant tuberculosis.

TB is an airborne disease that infects 9 million people and kills 2 million people each year.

The agency is recommending that the most affected countries install new TB treatment controls to avoid breeding multidrug-resistant TB strains, create new laboratories to manage epidemics, and invest more in drugs to treat existing cases. The WHO's Nunn says that by making relatively small investments up front, a country can head off severe dangers and expense later.

Nunn also warns that the hot spots where multidrug-resistant strains are occurring could become the sources for a worldwide epidemic. Nunn says that's because travelers can be infected with TB for weeks or months before showing any signs of illness.

"And then I'm told that something like 900 million people take to the air each year and cross an international border. So [the] vector [spreading agent] for this disease is the Boeing 747s, and they're not subject to vector control," he said. "So people can arrive all over the world infected with this disease. And passport controls don't work or controls at borders don't work."

The WHO report says the highest prevalence of multidrug-resistant TB coincides in Eastern Europe and Central Asia with the world's fastest-growing HIV infection rates. Tuberculosis is one of the main opportunistic infections that kills AIDS sufferers.

So these countries face a double hazard -- epidemic TB that resists ordinary drug treatment and widespread deaths among AIDS patients whose resistance to the disease is diminished.