In South Africa, 100 patients fled the hospital when victims of the new disease arrived. In Russia, 120,000 cases of the ailment were diagnosed in 2005 - yet most doctors have never heard of it.

And in Maricopa County, Ariz., a patient who defied quarantine now lives in a locked cell, guarded round the clock by a sheriff.

Extensively drug-resistant tuberculosis, or XDR-TB, has been identified in 26 countries, and is spread when victims cough. Yet unlike HIV-AIDS or avian flu, this sometimes incurable disease got almost no attention until recently. In part, that is because it spread suddenly, most visibly in the past year.

Now public health leaders here and elsewhere are trying to counter that silence. To prevent a potential pandemic, many say, governments and health organizations must fight the disease now.

XDR-TB currently is worst in South Africa, where it killed 52 of 53 patients in one hospital last year. Though treating tuberculosis was one of the last century's great triumphs, incomplete treatment breeds drug resistance.

Now, though most commonly detected in AIDS patients, XDR-TB infects HIV-negative patients as well. And though it thrives alongside poverty and malnutrition, tuberculosis can travel wherever one person coughs and others breathe. Houston's oil business and many travelers to and from Africa mean that even the excellent tuberculosis control programs here won't suffice if the disease isn't controlled overseas.

U.S. military and aid workers stand squarely in the bacterium's flight path. Many of these workers are stationed in Africa and in Afghanistan, which has the world's 17th highest TB rate. By 2008, the Pentagon will have fully established Africom, the new African military command center.

Houston, meanwhile, already is a world crossroads for military personnel, oil industry workers and civilian travelers.

This week, billionaire George Soros gave $3 million to a nonprofit coalition in Lesotho for XDR-TB prevention and research. The gift is urgently needed by that country to fight the disease - and as much, perhaps, in the industrialized world as a benchmark for how much still is needed. South Africa alone, the World Health Organization reckons, will need $650 million annually to study and prevent the disease.

In this country, Congress soon will vote on an emergency supplemental appropriations bill. Experts in global disease prevention, including Washington-based nonprofit RESULTS, are calling for this bill to include $300 million for fighting XDR-TB in Africa and $250 million to strengthen TB defenses in the United States.

The investment couldn't be more timely or wise. In the 1980s and 1990s, a single New York tuberculosis outbreak cost $1 billion to contain. And since last March, the number of countries where XDR-TB has been found jumped from 17 to 28.

At the rate this killer is traveling, ignoring it for much longer could be disastrous.