TB Cases in U.S. at Historic Low
CDC reports eighth straight drop in 2000, but some states still at risk
TUESDAY, June 12, 2001 (HealthDayNews) -- Tuberculosis rates in the United States have fallen for the eighth straight year, drawing closer to the elusive point of effective elimination in this country, new government figures say.
A report from the Centers for Disease Control and Prevention shows that the number of TB cases fell to an all-time low of 16,377 last year, down 7 percent from 1999. Since peaking at 26,673 cases in 1992, the rate of TB cases has dropped by 45 percent, and now hovers at under six per 100,000 people in this country.
Health officials, who released the figures as a run-up to a major TB meeting later this month in Baltimore, say they're pleased with the continuing decline in cases of the respiratory infection, which is caused by the bug Mycobacterium tuberculosis. However, they say, the drop hasn't met goals set last decade for conquering the disease. Officials had hoped that in 2000, the nation's TB rate would be 3.5 cases per 100,000, about 65 percent lower than the true figure.
"While the 2000 national TB figures highlight the effectiveness of U.S. TB control efforts, the disease still remains a significant health threat in many parts of this country," CDC director Dr. Jeffrey P. Koplan says in a statement. "To eliminate TB as a public health problem in the United States, efforts will need to be accelerated in those states and communities most affected by the disease."
TB remains one of the globe's leading killers, with 8 million new cases a year and 2 million deaths, officials say.
In addition to the national numbers, the agency released figures showing that three of the top 10 states for TB prevalence saw increases in the disease between 1999 and 2000. Alaska had the biggest jump, from 9.9 per 100,000 in 1999 to 17.2 per 100,000 in 2000. Arkansas and Georgia saw their rates climb, respectively, from 7.1 to 7.4 and 8.5 to 8.6 per 100,000 people.
Alaska officials say their presence at the top of the list reflects the added disease burden of two outbreaks, one involving nine patients from a single, large Anchorage family and another among villagers in southwest Alaska that accounted for 27 cases, of whom 13 were children. The infection was once rampant in Alaska, particularly among Native Americans there. In remote parts of the state, almost 90 percent of residents over the age of 60 test positive for exposure to the bacteria, officials say.
In the rest of the top 10 states -- California, New York, Hawaii, Louisiana, Florida, Texas and South Carolina -- TB rates fell.
Dr. Marisa Moore, a CDC expert familiar with the latest TB report, says increases in the disease are typically caused by either an influx of immigrants from countries where the disease is a problem or isolated outbreaks.
Still, Moore says, "every case is a potential outbreak. We can never really let our guard down or become complacent."
That includes keeping up directly observed therapy, in which health care workers monitor TB patients to make sure they stick to their full course of antibiotics. "The great therapeutic step that has been taken and that is responsible for lowering the rate of TB is the directly observed therapy. Without that, I dare say that we would not have made as much progress as what's been made," says Dr. Gerard M. Turino, director of the James P. Mara Center for Lung Disease at St. Luke's-Roosevelt Hospital in New York City.
The short course of directly observed therapy is six months, though some patients may need to stay on antibiotics for longer.
To further reduce TB, the government is pushing aggressively to identify people with latent, or non-symptomatic, infection. Between 10 million and 15 million residents of this country are believed to be carrying the bacteria that cause the disease, though only about 10 percent of those with healthy immune systems ultimately develop fulminant TB, she says.
In addition to immigrants and patients with HIV, AIDS and other conditions that suppress their immune systems, inmates and the elderly are groups at elevated risk of TB.
Tuberculosis was waning for most of the second half of the last century, officials say. But cutbacks in funding for TB control -- and the entrance of HIV and AIDS, which allow the bacteria in the immune system -- reversed those gains. TB cases jumped 20 percent between 1985 and 1992, when renewed vigor in screening, prevention and treatment helped bring them back down.
Another recent problem has been the appearance of drug-resistant forms of the germ, including strains immune to several antibiotics. Yet multiple-drug resistant TB is also in retreat, Moore says, accounting for just 150 cases a year.
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