Double Scourge: Tuberculosis and HIV Coinfection

uberculosis (tb) has, from ancient times, ranked among the most feared and dreaded of the many diseases that afflict mankind. Over a century since Mycobacterium tuberculosis was discovered and more than 50 years after effective drug treatment was introduced, tb remains a major public health problem. It is now five years since the World Health Organization (who) took the unprecedented step of declaring tb a “global emergency.” And yet more people died of tb last year than in recorded history—2 to 3 million deaths, or 1 death every 10 seconds. Eradicating tb, even within the borders of industrialized nations, continues to be a significant challenge. In 1989, the U.S. Public Health Service Advisory Council on the Elimination of Tuberculosis was established and proposed the tb Elimination Strategy—defined as a case rate less than 1 per 1,000,000 people—to be completed by the year 2010. With only eight years remaining, thousands of tb cases continue to be reported annually in the United States. In turn, new recommendations toward the goal have been established, including more aggressive screening and early treatment approaches, particularly among those at the greatest risk for tb: persons living with hiv and aids. TB in the U.S.: Better but Not Gone during the 19th century, tb claimed more lives in the United States than any other disease. With improvements in nutrition, housing, sanitation, and medical care in the first half of the 20th century— along with the introduction of effective antibiotic therapies in the 1940s and ’50s—the disease was finally in retreat. In 1985, however, the decline ended and the number of active tb cases in the United States began to rise again, a trend that was undeniably associated with the rapidly growing aids epidemic. Over a sevenyear period, the number of new tb cases soared by 20%, from 22,201 cases in 1985 to 26,673 cases in 1992 (see Figure 1). Fortunately, this dramatic climb was again reversed with the restrengthening of tb control activities, including aggressive screening and treatment of those considered to be at risk for symptomatic disease. In 2000, a total of 16,377 cases of active tb were reported to the U.S. Centers for Disease Control (cdc). This represents a 45% drop since 1992, from 10.5 cases per 100,000 people in 1992 to 5.8 cases per 100,000 in 2000. But the United States is not out of the red just yet: The cdc estimates that 10 to 15 million people in the U.S. have latent tb infection, and about 10% of them will go on to develop active tb at some point in their lives unless more aggressive steps are taken to lower these odds. The ten states that led the nation with the highest tb rates in 2000 were (in ranking order) Alaska, Hawaii, California, New York, Georgia, Arkansas, Louisiana, Florida, Texas, and South Carolina (see Table 1). Seven of these states had a decrease in tb rates between 1999 and 2000, but three states—Alaska, Arkansas and Georgia—reported increases in rates. Alaska had the most dramatic rise in rates, from 9.9 in 1999 to 17.2 in 2000. tb rates in Arkansas climbed from 7.1 to 7.4, and the rates in Georgia increased slightly from 8.5 to 8.6. As for tb rates in New York City, 1,332 new cases of active tb were reported in