Case totals reach plateau according to 2001 data, but what does it mean?

Congress urged to allocate more money

Last year TB rates in the United States fell just 2%, marking an end to an eight-year run of declines averaging 7%. While it’s too soon to say whether the flattening curve is the start of something new, TB experts say the numbers may be an omen.

"A trend toward leveling was the first sign we had in the mid-80’s that we were about to get in a lot of trouble," says Philip Hopewell, MD, associate dean of the University of California/San Francisco and a member of the Institute of Medicine Committee on the Elimination of Tuberculosis.

"While this single yearly change does not by itself constitute a trend, it provides an early warning of possible stagnation of recent progress," added Ken Castro, MD, in remarks delivered in the days leading up to World TB Day on March 24. Castro is director of the Division of TB Elimination at the Centers for Disease Control and Prevention.

The 2001 case numbers were announced in conjunction with World TB Day. The National Coalition to Eliminate Tuberculosis used the occasion to urge Congress to double federal funding for TB, a move that would raise this year’s allotment of $132 million to $265 million for FY 2003.

Years of flat funding taking toll?

Federal funding for TB programs has been flat for the past eight years in a row, and Hopewell says that may be what’s behind this year’s plateau. "If you take the long view over the past several decades, you find that every time there’s been a reduction or leveling of funding, case rates either level off or in some instances increase," he says.

Fully half of all cases last year occurred in the foreign-born. That’s up from 46% the year before, federal TB experts say. Immigrants from Mexico, the Philippines, Vietnam, and India accounted, in that order, for the most foreign-born cases. The increase in the proportion of foreign-born TB cases means that, more than ever, fighting TB at home will call for fighting the disease worldwide, Health and Human Services Secretary Tommy Thompson noted in a speech on World TB Day.

Multiple initiatives are under way targeting TB among the foreign-born population, including the following:

  • Overseas screening procedures are being scrutinized closely. A pilot program being planned for Vietnam will use Quantiferon, the new diagnostic test for latency.
  • A new binational TB card has been proposed to ensure patients traveling between the United States and Mexico complete their TB therapy.
  • For deportees with active TB, high-level government discussions are under way aimed at ensuring treatment is completed.
  • An electronic notification system, once it’s up and running, will expedite the process of letting states know when a case is headed their way.

Countries heavily burdened by TB need an additional $300 million to meet targets for implementing directly observed therapy-short course, according to a survey by the World Health Organization. Still, there’s cause for optimism, TB experts say. For one thing, the Global Fund to Fight HIV/AIDS, Tuberculosis and Malaria has raised about $1.9 billion in pledges so far. About $700,000 of the pledges will be disbursed this year. So far, the U.S. has pledged only $100 million to the fund, but a bill introduced recently in the Senate by Barbara Boxer (D-CA) and Gordon Smith (R-OR) seeks to double that amount for next year.

Low-incidence states caught short

Other trends are also emerging from an analysis of last year’s case information. The disease is increasingly apt to strike low-incidence states, which are often ill-equipped to identify TB or to handle surges in case numbers, Castro says. The low-incidence outbreaks underscore the importance of maintaining a core infrastructure and access to expertise, even in states or regions that see relatively few cases, he adds.

A recent Morbidity & Mortality Weekly Report detailed one such outbreak, which took place on an Indian reservation in Fort Belknap, MT.1 In that episode, four drinking buddies of the index case were eventually found to have contracted active disease. But until federal experts arrived, local public health authorities (who hadn’t seen a case of TB in nearly a decade) were thrown off the trail and lost valuable time checking the man’s household contacts instead of his carousing pals.

Whether you’re talking about low-incidence outbreaks or an increase in TB among the foreign-born, the new trends all point to a single imperative, say TB experts: If TB is ever to be wiped out in the United States, more dollars must be allocated to local and state programs. "The remaining cases increasingly are found in populations that are harder to access and that require more intensive efforts to provide prevention and control," says Hopewell.

Reference

1. Tuberculosis outbreak on an American Indian reservation—Montana, 2000-2001. MMWR 2002; 51:232.