Resistant TB on the rise in Western countries

Denmark, Germany, New Zealand see increases

TB controllers in some Western countries who thought they might be spared the rising global tide of TB resistance are beginning to feel the water lapping at their toes, suggests a new report on global TB resistance from the World Health Organization.

"Findings from Western countries show that multidrug-resistant TB [MDR-TB] has established, if not a beachhead, at least what I’d call a toehold," says Nils Daulaire, MD, president of the Global Health Council, an advocacy group based in New York City. "It also shows that MDR-TB has established a solid hold in lots of countries around the world: in Iran, surprisingly, and also in Estonia, Latvia, India, China, and Russia."

In Denmark, the proportion of cases resistant to at least one drug rose from 8.8% in 1996 to 13.4% in 1997; in Germany, from 7.7% in 1997 to 10.3% in 1998; and in New Zealand, from 4.8% in 1996 to 12% in 1997.

Drug resistance should be considered threat

The proportion of MDR-TB cases in those countries is lower, at less than 2%. Foreign-born patients in the three countries are twice as likely as native-born patients to be harboring a drug-resistant strain. In the United States, the report says, resistance to at least one drug is down slightly, from 12.9% in 1995 to 12.4% in 1997.

During that same period, MDR-TB in the United States fell from 2% to 1.4%, but in Mexico, America’s neighbor to the South, 20.6% of cases show resistance to at least one drug; and 6% of new and previously treated cases represent multidrug-resistant TB.

The time when critics could say TB advocates are "over-promoting the issue" of drug-resistance has come and gone, adds Daulaire. "It’s now clear that MDR-TB has become an important and growing concern."

Daulaire praises the WHO report for its ability to show how swiftly resistance rates are rising in hot spots around the world. In Estonia, at the top of the list, the percentage of MDR-TB stood at a whopping 18.1% in 1998, up from 13.5% in 1997.

MDR-TB also accounts for more than 3% of all new cases in the following areas:

• two provinces in China;

• India;

• Iran;

• Mozambique;

• an oblast in Russia.

In Mexico, Italy, and Israel, MDR-TB is found in more than 6% of both new and previously treated cases.

By the yardstick of resistance to at least one drug, the report shows 13 areas in which total caseloads reflect resistance rates of 20% or more (listed in box):

Countries in which DOTS has been employed rigorously are finding that resistance rates are leveling off or even starting to go down. In parts of China where DOTS has been implemented, resistance rates are three times lower than in non-DOTS regions, and in Cuba and Nepal, resistance rates are heading downward as well.

There are exceptions to that rule, however. In Botswana and Tanzania, good DOTS programs show evidence of being overwhelmed by HIV.