Tuberculosis (TB) cases are decreasing for the first time in more than 20 years, the World Health Organization announced on Tuesday. But that progress may be jeopardized if Congress cuts foreign aid for prevention and treatment programs.

There were 8.8 million new cases of TB in 2010, down from 9 million in 2005. This means the downward trend has been going on for some time, but it was only just confirmed in WHO's 2011 Global Tuberculosis Control Report.

Altogether, 12 million people are living with an active TB infection, and 650,000 of them are infected with multiple drug-resistant strains. About 59 percent of the new cases were in Asia, 26 percent in Africa and only 3 percent in the Americas, according to the WHO numbers.

Because people with AIDS are 30 times more likely to contract TB than healthy people, the number of new TB cases has been increasing for most of the 25 years since the AIDS pandemic began, so the new numbers are significant.

Efforts to combat TB are inevitably linked to efforts to combat AIDS. As the number of AIDS cases in Africa has plateaued, there has been a natural decrease in TB cases, furthered by foreign aid from the United States and other Western countries for prevention and treatment efforts.

Aid May Be At Rick, Due to Austerity Measures

But that aid may be at risk, as it is among the expenditures that Congress is considering cutting in the latest round of budget talks. A decrease in U.S. aid, which is currently about $375 million a year, would be devastating for anti-TB efforts.

This momentum could be turned into complacency, Mario Raviglione, the head of WHO's Stop TB Department, told The Washington Post. Without the U.S. government's investment, we would have stagnation for the next few years.

It was for that reason that WHO decided to announce the decrease in TB cases in Washington, rather than in Geneva, where the organization has its headquarters. WHO officials hope that the proof that anti-TB programs are having an impact will make Congress think twice about cutting funding.

The U.S. Senate's proposed 2012 budget would not cut anti-TB funding, but the House's version might. The House wants to cut President Obama's $7.83 billion Global Health Initiative by $700 million, but efforts to combat TB are only part of the Global Health Initiative, and it is unclear which elements would be cut if the House passes its proposed budget.

Tuberculosis is one of the oldest known diseases, with evidence of infections for at least 15,000 years. Today, it is the second-deadliest infectious disease in the world, behind AIDS. In 2010 alone, 1.4 million people died of TB.  

Although the number of new TB cases has only started to decline in the past few years, the number of deaths has been falling for some time. The TB mortality rate in China has dropped by nearly 80 percent over the past 20 years, and mortality rates in Brazil, Cambodia and Uganda have dropped by about 50 percent over that same period.