Hard to Kill: The TB Superbug

A Chinese doctor examines an x-ray of a tuberculosis patient at the Beijing Tuberculosis Hospital. Tuberculosis remains the most deadly infectious disease in China accounting for more than 250,000 deaths each year. China, which has more than six million tuberculosis patients who are mainly from rural areas, has been working closely with the World Bank and World Health Organisation to control the disease. Reuters

You might not recall hearing about an undocumented Nepalese man who was picked up by U.S. border cops in south Texas a year ago. His case didn't make the news at first, perhaps because federal health officials wanted to avoid a panic. But earlier this year, when a Wall Street Journal reporter finally broke the story, it was clear right away why the feds were nervous. The detainee was suffering from a particularly nasty disease - contagious, tough to treat, and potentially deadly. It was the superbug they call "extensively drug-resistant tuberculosis," XDR-TB for short.

Ordinary tuberculosis is bad enough. Once the leading cause of death in the United States, the airborne disease still ranks second only to AIDS in worldwide fatalities from contagious illness, with 1.3 million dead last year alone, according to the World Health Organization. Of people infected by the bacterium, only 10 percent or so will ever develop an active case of tuberculosis. But those victims will need six months or more of continuous, closely supervised anti-TB drug treatment. Without that, the odds are two out of three that the disease will eventually kill them.

Worse yet, the threat is evolving - not only in the developing world, but also inside the United States, where the Centers for Disease Control and Prevention recorded nearly 10,000 cases of TB last year. Tuberculosis germs are tough, and if a patient's course of treatment is interrupted, drug-resistant strains can develop and infect other individuals. The same can happen when health-care providers prescribe the wrong medicine, the wrong dose, or too short a course of treatment. And the necessary drugs and medical services are too often in short supply in some poorer areas, even in our own country.

The danger is real. Last year, according to the WHO, an estimated 450,000 people around the world developed multidrug-resistant tuberculosis (MDR-TB) - that is, a variant strain that can't be cured by the first-line drugs routinely used against ordinary tuberculosis. Treatment of those cases requires an extended course of second-line drugs, which tend to be more expensive and a lot tougher on the patient's underlying health - when they can be obtained at all.

As if that concern isn't serious enough, badly treated cases of MDR-TB can give rise to the even more virulent XDR-TB, like the strain that infected the Nepalese traveler. According to the WHO, nearly 10 percent of the world's MDR-TB patients are suffering from extensively drug-resistant variants of the disease. For those victims at least two of the most-prescribed second-line drugs are as useless as first-line drugs are for victims of ordinary MDR-TB. Their only hope is at least two years of high-priced, high-risk treatment. Even then the prognosis is poor.

MDR-TB has been present in the United States for many years, and although it remains comparatively rare, it's not going away. There were 127 cases reported in 2011, the most recent year for which complete figures are available, and epidemiologists are convinced that a significant share of them were homegrown, not imported. XDR-TB has been even scarcer, with only 63 confirmed cases in the past 20 years.

But public-health experts are concerned about a major drug-resistant outbreak in the U.S. It's a genuine risk among the nation's poor, especially those without access to basic medical care. And there's no way to ignore the massive inmate populations of America's prisons and immigrant detention centers - overcrowded and underfunded facilities that are petri dishes for all sorts of communicable diseases. Many of those convicts and asylum seekers ultimately go free, whether or not they're sick.

Government policies are supposed to protect the public, but the system isn't foolproof, and some cases slip through. Protection against TB depends on a complex coordination of state, local, and tribal health departments, each receiving expert guidance and resources from the CDC. The task is to spot cases of the disease as promptly as possible, and then to comply with U.S. standards requiring public-health workers to ensure the patient receives and takes the necessary drugs, often on a biweekly basis and continuing for a year or more.

The trouble is that America is such a transient society. Despite the need for uninterrupted treatment, local health authorities are handicapped in efforts to keep track of tuberculosis patients who relocate. The country's public-health apparatus is fragmented, and often when a case crosses from one jurisdiction to another, there's no way to make the handoff, or even to locate and warn people who may have been exposed in transit.

On top of everything else, there's the problem of money. TB treatment is time-consuming and expensive, even for the most routine, nonresistant occurrences of the disease. Nevertheless, budget hawks in Congress have cut the funds the CDC receives for allocation to state TB programs. Compounding the damage, cash-strapped state and municipal governments have reduced their own public-health funding.

Heroic public-health professionals across the country are somehow finding ways to surmount many of these difficulties. Eventually, however, a crisis seems all but inevitable. Public health is always "local," in the sense that it's primarily about individuals, their loved ones, and communities. But preventing epidemics requires a broader vision and long-term investment. Unfortunately, budget cutters seem blind to human costs.

Polly Price is a professor at Emory Law School