World turns a corner on TB

For the first time in modern history, the rate of infections in the global tuberculosis epidemic has leveled off and might be on the "threshold of decline," the World Health Organization announced Thursday.

The percentage of the world's population struck by TB peaked in 2004 and then held steady or even declined in 2005, according to the report. "This is a breakthrough," said Dr. Marcos Espinal of WHO's Stop TB Partnership. "It's the first time we've had good news about the epidemic since 1993."

In Africa, the TB rate was 343 cases per 100,000, more than twice the global rate, indicating the continuing challenge there.

And while the global rate remained steady, the actual number of people with TB increased because of population growth. In 2005, there were 8.8 million new tuberculosis cases, and 1.6 million deaths, the WHO said.

Dr. Mario Raviglione, director of the WHO's anti-tuberculosis effort, said the figures represented the first time ever that TB rates have declined. "Incidence has peaked around the world," he said. "This is fruition of all our efforts."

The announcement marks a milestone in the fight against TB, which was declared a global health emergency by the WHO in 1993 because of skyrocketing infections. Since then, the number of deaths has declined from more than 3 million to 1.6 million in 2005, according to the report.

The epidemic is centered primarily in Asia and sub-Saharan Africa.

"Nearly 60 percent of TB cases worldwide are detected and, out of those, the vast majority are cured," U.N. Secretary-General Ban Ki-moon said in a prepared statement. "Over the past decade, 26 million patients have been placed on effective TB treatment."

Despite the progress, Dr. Lee Reichman, executive director of the Global Tuberculosis Institute at the University of Medicine and Dentistry of New Jersey, cautioned that TB remains a wily opponent.

One of the major concerns is the emergence of "basically untreatable TB" — strains of the disease known as multi-drug resistant and extensively drug resistant TB.

Experts fear that either or both of those strains could get a stronger foothold, reversing the current successes in treatment. Treatment of drug-resistant strains of TB costs nearly twice as much as treating conventional TB and takes much longer.

"With TB, we have learned through painful lessons that you should never declare victory prematurely," said Dr. Kenneth Castro, director of the division of tuberculosis elimination at the federal Centers for Disease Control and Prevention. "The moment you relent, TB has an incredible ability to come back with a vengeance."

He noted that TB seemed to be firmly under control in the United States in the mid-1980s, but that the rate started climbing again when chest clinics were closed and TB funds were diverted to other diseases.

Tuberculosis is one of the oldest diseases known to man. It is an often-lethal infection of the lungs characterized by fever, weight loss, night sweats and coughing up blood.

Saturday, World Tuberculosis Day, marks the 125th anniversary of German bacteriologist Robert Koch's discovery of Mycobacterium tuberculosis, the microorganism that causes TB.

Unlike most common infections, tuberculosis is difficult to cure. Treatment of an active infection usually entails taking four antibiotics for two months, then two antibiotics for another four months. In the past, patients often stopped taking their drugs after a few weeks, leading to a recurrence.

Incomplete treatment is the primary source of drug-resistant TB.

One of the major reasons for the improvement in cure rates noted by WHO is the implementation of a technique called directly observed therapy, in which health workers watch patients swallow each dose of the drugs.

Nearly 90 percent of the world's population lives in areas where public-health services have implemented directly observed therapy programs, the report said.

Raviglione attributed some of the gains in tuberculosis control to a slowing of the HIV epidemic in Africa. TB preys on immune-compromised AIDS patients and is nearly always lethal — killing 195,000 AIDS patients in 2005.

Castro also cited an increase in political will to fight the disease: Countries such as China and Russia have committed to make tuberculosis a priority and to fund programs against it.

Total funding has nearly doubled since 2002, reaching about $2 billion this year. That figure reflects not only increased funding from donor nations but also substantial increases in domestic funding in China, the Russian Federation and South Africa.

Current funding levels are not high enough, however, according to the report. An additional $1.1 billion will be required in 2007 to meet the requirements set by the Global Plan to Stop TB, established last year.

Information from The Associated Press is included in this report.