World TB cases decline for first time

The number of people getting sick with tuberculosis has dropped for the first time, while the death toll from the disease reached its lowest level in a decade, helped by progress in countries like China, the World Health Organisation said today.

In 2010, 8.8 million people fell ill with TB and 1.4 million died, both marking a notable decline over prior years, the United Nations health agency said in releasing its 2011 Global Tuberculosis Control Report.

"The findings reflect a significant milestone for global health," said Dr. Mario Raviglione, director of the WHO's Stop TB Department, at a news briefing. "But history teaches that we cannot be complacent about TB. The international community therefore must not perceive these achievements as job done."

TB is a worldwide pandemic, with about a third of the world's population infected with the bacteria, although only a small portion ever develop the disease.

The WHO has revised its estimates to show that the absolute number of cases has been on a decline since 2006, not on a slight rise as previously reported. The number of people ill with TB peaked at 9 million in 2005.

The death toll from TB peaked at 1.8 million in 2003.

The WHO officials attributed the decline to better data collection around the world; increased funding in China for addressing TB; better prevention and care in the former countries of the Soviet Union and Latin America as their standard of living improves; and a drop-off of infection in Africa, which had peaked with the HIV epidemic.

The TB bacteria destroys patients' lung tissue, causing them to cough up the bacteria, which then spreads through the air and can be inhaled by others. If untreated, each person with active TB can infect on average 10 to 15 people a year.

TB is especially common in Latin America and the Caribbean, Africa, Asia, Eastern Europe and Russia.

The countries the WHO especially noted for progress in the fight against the disease were Kenya, the United Republic of Tanzania, Brazil and China, which saw a drop of nearly 80 percent to 55,000 TB deaths in 2010 since 1990.

Globally, the TB death rate dropped 40 percent in 2010 compared to 1990, and all regions except Africa were on track to reach a 50 percent mortality decline by 2015.

Some countries routinely vaccinate children with Bacillus Calmette-Guerin, made by several companies including Merck & Co Inc. The vaccine doesn't always protect against TB.

The infection is also treatable by antibiotics, such as isoniazid or Sanofi's Rifadin, but they must be taken daily for months to be effective.

Because people do not always take the drugs as directed, multidrug-resistant (MDR-TB) and extensively drug-resistant (XDR-TB) strains have emerged. Leaving them untreated increases the risk of drug-resistant strains of TB spreading.

In March of this year, the WHO warned that more than 2 million people will contract MDR-TB by 2015.

Drug-resistant TB strains remain one of the biggest challenges, as only about 16 percent of patients diagnosed with MDR-TB are actually getting treatment, said Dr. Katherine Floyd, coordinator of the TB monitoring and evaluation unit at the Stop TB department.

"There is little interest by the industry in developing new drugs in general for antibiotics, but when it comes to TB in particular ... they cannot count on making a lot of money off the drugs and therefore don't invest," Raviglione said.

Although many advances have been made in increasing access to diagnostic technology, clinics and treatment around the world, countries pay for some 86 percent of all anti-TB funding and continue to struggle with funding gaps.

With that in mind, global health experts warned against complacency about the reported improvement.

"We know from the past experience that as soon as you drop the guard, TB comes back," said USAID's Dr. Ariel Pablos-Mendez.