U.S. Faces TB Threat

0 Comments | Insight on the News, Jan 31, 2000 | by August Gribbin

Researchers say cuts in spending presage `catastrophe' from drug-resistant strains of tuberculosis, a disease held in check since 1945. The costs of containing TB could be `staggering.'

The United States is curtailing efforts to control tuberculosis just when new lethal strains are threatening what some fear could become a public-health catastrophe. Harvard Medical School researchers have documented cases of multidrug-resistant tuberculosis, or MDR-TB, in 100 nations. Increasingly, foreign visitors and immigrants from underdeveloped countries are bringing the disease into this country.

The contagion has not yet caused dramatic spikes in health statistics or generated a stampede of concern. But TB develops slowly and not everyone who is infected develops symptoms. Then too, most Americans know little about tuberculosis, an infection that can affect various parts of the body, producing lesions and sometimes attacking the brain and spinal cord.

Typically, TB lodges in the lungs. It makes breathing difficult; induces a fierce, nagging cough; and causes exhaustion, weakness, a steady fever, nighttime sweating and bloody phlegm. Before the 1940s, "consumption," as it was called, devastated entire communities. In those days, families were split and incomes imperiled when a parent was forced into a hospital isolation ward or sanitarium to undergo harrowing treatments for months or years. Many patients had portions of their lungs collapsed or removed to save them from the disease that for decades was the nation's leading cause of death.

Then in 1945 antibiotics arrived, and the wonder drugs revolutionized treatment. Doctors eventually determined that treating patients with a combination of drugs over the course of six to nine months could cure victims 70 to 90 percent of the time. Indeed, cures were expected in most of the 18,371 active TB cases reported to the U.S. Centers for Disease Control and Prevention last year.

MDR-TB is something else, however. Drug-resistant tuberculosis have mutated and can fend off conventional medicines. Such strains are much harder to cure -- often they are incurable. Physicians treat the disease by administering various combinations of expensive, infection-fighting drugs over long periods. Treating a single such patient costs $250,000 -- considerably more in extreme instances when a patient must be quarantined -- actually isolated -- for life.

Although some 8 million people around the globe contract TB each year and some 3 million die, no one knows for sure how many now have drug-resistant TB. Based on incomplete data, the World Health Organization three years ago reported 50 million cases; researchers estimate that at least 2.5 percent of these victims are infected with drug-resistant tuberculosis.

Since then, physicians studying hot spots of TB infection in places such as Argentina, China, the Dominican Republic, India and Russia have found that 7 to 22 percent carry the drug-resistant variety. That's roughly three to 10 times the expected rate. Consider that currently only 60 percent of all TB cases worldwide are ever diagnosed and fewer than 60 percent of those are cured, and the seriousness of the problem comes more clear.

"I don't want to be hysterical; I don't want to say each of us is threatened," says Barry Bloom, dean of the Harvard School of Public Health. "But there is no place from which we are distant and no one from whom we are disconnected when dealing with infectious diseases like TB."

A dire prognosis rests on several realities. Foremost is the fact that tuberculosis bacteria, including drug-resistant strains, spread with remarkable ease -- by the cough or sneeze of a TB victim.

"A person with the active disease can cough in a room and leave. Someone then entering the room and breathing the air can contract the infection," explains Jim Yong Kim, who wrote the Harvard report with Paul Farmer, the principal author. TB victims riding planes, buses, trains and other public transportation carry the disease across borders, infecting fellow travelers, customs agents and others on the way. On average, each person with active TB infects 20 others.

Complicating matters further, MDR-TB cannot be determined by testing. Drug resistance is diagnosed only when the patient becomes sicker and sicker despite standard chemotherapy. As a result, MDR-TB can emerge as a significant problem even in settings with excellent TB control, as happened in Peru.

Along with many others, the Harvard researchers are calling for quick action to combat the "pandemic." The costs of fighting the new menace "are likely to be staggering," note the authors of the report, and must fall heavily on developed nations and philanthropic groups. Nevertheless, treating victims in nations where the disease already is epidemic provides the best protection for the United States -- it limits the number of foreign visitors and immigrants capable of infecting Americans.

While the peril posed by the slowly building pestilence has not pierced the U.S. public's perception, none of the physicians, technicians or administrators in tuberculosis research or control questions the Harvard study's findings or conclusions. Yet there still is no visible evidence the United States is preparing to respond to the challenge, according to Kim, who believes "governments have not been appropriately concerned and generous." More important, says Bloom, "both the states and the federal government are cutting their tuberculosis programs. They're firing TB-control officers. We set up a fantastically effective anti-TB system from 1993 to the present, and now we're in the process of dismembering it."