Every three minutes, more people die from TB than have died from the deadly and scary SARS virus since it was first known to strike a couple of weeks ago.

Since the TB bacterium was discovered in 1892, 200 million have died. And that number is going up two to three million a year.

Those horrifying numbers put TB in the big league of infectious killers, up there with AIDS and malaria, each of which kills roughly equal numbers.

AIDS, of course, is far more prominent on the radar screens of Western governments and charities than the other two diseases.

That's partly because it still frightens people in rich countries as well as poor ones. Because it has effective, well organized advocates. And because it's a fairly new disease with an aura of mystery in that a lot about it is not understood.

Meanwhile, TB and malaria have been around far longer than humans can remember. They're old hat, not seen as threats in rich countries--though TB perhaps should be, as it crosses borders with impunity in this global era. And they're seen as easy to cure -- though once again TB should perhaps be regarded otherwise with the advent of drug-resistant strains.

The upshot of these attitudes is that AIDS gets about two-thirds of the international money to fight killer diseases in the Third World, and TB and malaria get much, much less.

The irony is, however, that for anyone constrained by financial resources-- that is every medical team at work in the developing world--and concerned about saving lives, TB and malaria are much more cost effective targets. It costs about one-seventeenth as much to save a TB victim as an AIDS victim, a thirty-eighth as much to cure malaria, and much less again to prevent it.

This is not an excuse to abandon the fight against AIDS, of course, but it should give pause for thought about how both governments and charities apportion their foreign aid budgets.

Today, March 24, is World Tuberculosis Day-- a good time to give the issue some thought.