Despite significant advances in the treatment of tuberculosis, experts say the disease remains a vast global health problem, affecting one-third of the world's population. Health officials say intensive efforts are needed to reach an international goal of cutting in half the number of TB infections and deaths by 2015.
Few diseases, including AIDS, rival tuberculosis in scope. Experts say two million people die each year of the highly contagious illness, which strikes approximately eight million individuals annually. According to officials, tuberculosis kills someone every 27 seconds.
About 97 percent of the TB cases are in the developing world. Half of the afflicted live in Bangladesh, China, India, Indonesia and Nigeria.
The lung disease is curable if caught and treated in time. Treatment usually consists of faithfully taking one or two inexpensive antibiotic drugs for a period of six to nine months.
But officials are alarmed by the growing threat of multi-drug-resistant tuberculosis (MDR TB) when the disease does not respond to antibiotics. Officials say MDR TB occurs when people with tuberculosis do not take their medications long enough, or they spread MDR TB to those who are not infected.
Reuben Granich is the author of an article in the June 8 edition of the Journal of the American Medical Association (JAMA) devoted to tuberculosis.
Dr. Granich of the U.S. Centers for Disease Control in Atlanta says MDR TB can be lethal, especially to AIDS patients with compromised immune systems, and it's harder to treat. He says MDR TB also threatens conventional tuberculosis control efforts.
"It has a more prolonged infectious period," he said. "It is harder to kill the bacterium, and people spread it for longer. It's very, very expensive. Most cases [of MDR TB] can be treated for less than $200,000, but some individual cases can cost over $1 million to treat and control."
Surveys published in JAMA show that multi-drug-resistance has increased significantly in 10 regions, including Kazakhstan, Israel, Uzbekistan, Estonia, China and Equador.
The TB epidemic is being fueled by its spread among people infected with HIV. Also in JAMA, Alison Grant of the London School of Hygiene and Tropical Medicine, reports on using the standard TB drug, isoniazid, to prevent infection in South African gold miners who were at risk for TB because they were HIV positive.
The study, which took place between 1999 and 2001, involved just over 1,000 men. Overall, the drug kept 38 percent of them from developing tuberculosis.
Dr. Grant says isoniazid may be used along with more conventional strategies to combat tuberculosis in a community setting.
"That's basically taking everyone in a community and screening them for TB, obviously treating anybody who has active TB, but offering preventative therapy to everybody to see whether you can really cut transmission to try to bring down TB rates rapidly," she explained.
But Dr. Grant called unacceptably high a tuberculosis infection rate of nine percent in the South African community where she conducted her study.
The World Health Organization (WHO) adopted a plan, as part of its so-called Millennium Development Goals to improve health and eliminate poverty, to slash the number of new cases of tuberculosis each year from eight million to four million by 2015. The plan also calls for cutting the number of TB deaths to under one million.
The centerpiece of the plan is DOTS, which stands for directly observed therapy. It's an aggressive strategy, which includes diagnosing people with TB and having local public health workers stand over them, while they take their low cost antibiotics.
The head of the WHO's tuberculosis eradication effort, Christopher Dye, says DOTS is responsible for containing or lowering TB rates in many parts of the world. But, he says, there's still a long way to go, particularly in those African countries where high rates of HIV infection increases the risk of tuberculosis.
"I'm rather optimistic about what we can achieve in the big Asian countries, because they are now doing TB control on a very large scale," he added. "I have to say I am somewhat less optimistic about what we're seeing in Africa. Africa is going to need an enormous amount of support to meet the Millennium Development Goals, and particularly to achieve that very challenging target of halving the [TB] death rate by 2015."
But in the end, Mr. Dye says, the countries themselves must have the political will to eradicate tuberculosis to stop the epidemic.