TB: A Global Epidemic, a Curable Disease

By Kristi Birch

This year, tuberculosis will kill 2 million people. According to the World Health Organization, another 2 billion people are infected with TB, and more than 9 million new cases occur annually.

And yet the disease is almost entirely curable. Today’s standard treatment—four drugs taken once a day for two months, and then two drugs for the next four months—cures TB 95 percent of the time, as long as the course of medicine is completed. But many stop too early.

Moreover, strains of TB have emerged that are resistant to isoniazid and rifampicin, the two most powerful anti-TB drugs. And HIV has provided the perfect vehicle for TB’s spread, making it the leading cause of death for people infected with HIV.

So how to control TB? “There isn’t a magic bullet,” says Richard Chaisson, MD, professor of Medicine, Epidemiology and International Health, and the director of Hopkins’ Center for Tuberculosis Research, where researchers are working on new vaccines to prevent TB, new tests to diagnose it and new treatments that take less time. And they’re devising new preventive therapies to keep the mycobacterium inactive in infected people.

Chaisson doesn’t expect to see TB wiped off the planet—not with a “reservoir of 2 billion infections. The goal for TB,” he says, “is just to control it so that it is not an epidemic.”

Some Facts about TB

Alaska's rate of TB plummeted during the past 50 years, but the state still has one of the highest rates in the United States, with 8.8 cases per 100,000.
In the United States, 14,874 TB cases were reported to the CDC in 2003, representing a 44.2 percent decrease from 1992. But many new cases seen in the U.S. are multidrug-resistant strains that are difficult to combat.
TB is the leading cause of death among people with HIV—accounting for about 11 percent of AIDS deaths worldwide.
In Peru, widespread implementation of the directly observed therapy strategy has prevented an estimated 70 percent of deaths among infectious cases from 1991 to 2000.
The estimated incidence per capita in sub-Saharan Africa is nearly twice that of Southeast Asia, at 350 cases per 100,000 population.
A recent wave of Russian immigrants to Israel sent that country’s TB rate up more than 50 percent.
In South Africa alone there are 2 million adults co-infected with HIV and TB.
The TB death burden is not evenly spread: Developing countries have 90 percent of the world’s TB burden. India alone has 30 percent (with some 2 million new cases reported there annually).
About one in three of the 42 million people living with AIDS are co-infected with TB, according to the WHO; 90 percent of them will die within a few months without the right treatment.
Russia’s collapsing economy, overcrowded prisons and overburdened medical system have created one of the world’s worst epidemics of drug-resistant TB.
In China, an estimated 250,000 people die each year from TB.
One-third of the world’s new TB cases occur in Southeast Asia.
The cost for treating a multidrug-resistant case of TB can exceed $250,000 per person and take up to two years for successful completion.