Once again, the virus that conjures special images of fear among scientists and the general public has surfaced. And, once again, it has emerged in the poorest parts of central Africa.

Ebola.

Few members of the viral world evoke as many Stephen King-like notions of horror and human frailty. It's hardly a major killer in the global scheme of things. Even when compared to other flash-in-the-pan outbreaks, Ebola epidemics cannot, by virtue of numbers of people killed, be considered a top concern on the health radar screen.

And yet this deadly filovirus merits international concern, not only in its own right, but as a harbinger of things to come. We ignore the current epidemic in Gulu, Uganda at our collective peril.

The Ebola virus, which first came to international attention when it broke out in a missionary hospital in Yambuku, Zaire in 1976, is a member of a thankfully tiny club of hemorrhagic fever agents. It specifically targets the endothelial tissue that comprises the linings of blood vessels, arteries and capillaries, eating away microscopic holes in the body's vital conduits. From these holes drain first water molecules and later, as the leaks expand, red blood cells. Hemorrhaging may occur anywhere in the body, and patients can become terrifying to view as blood pours from their noses, mouths, eyes and all other orifices.

The virus can be passed from one person to another a number of ways--primarily through direct contact. Scientists have recently isolated Ebola viruses from the sweat, blood, saliva and lung tissue of those sorry individuals autopsied during the 1995 Ebola outbreak in Zaire. That epidemic was brought under control through a strategy that sought to limit the skin-to-skin contacts between infected individuals and their healthy, living caretakers.

The take-home lesson of the 1995 epidemic was simple: poor, under-resourced hospitals in which basic elements of public health are ignored serve as vectors for epidemics. There never would have been an Ebola epidemic in Kikwit had there not been a looted, decrepit hospital into which the first handful of cases were admitted. Once inside a facility that lacked any modicum of hygienic practices the virus spread rapidly, first claiming large numbers of health care workers, and then their patients.

The World Health Organization team that responded to the epidemic--five months after it began, illustrating a failure in global disease surveillance--simply implemented classic early-20th-century public health measures. No high-tech solutions were needed: hand washing, quarantine, cessation of funeral practices, contact tracing and public education about the virus were sufficient to conquer Ebola.

The current outbreak in northern Uganda once again finds the virus taking advantage of poor medical facilities and funeral practices. And, once again, classic public health efforts are in place to bring the epidemic under control. Like its predecessor in Zaire, this outbreak has come to world attention months after it began, and only when health care workers, including foreigners, have succumbed. The full scope of the epidemic, including evidence it may also be expanding in Sudan and southward towards Uganda's capital city, Kampala, has yet to be determined. Regardless of how large its scope may be, however, the same control measures will ultimately be effective.

In the two large Zaire outbreaks Ebola emerged in areas so remote that there was little, if any, threat of spread to other countries, including the U.S. Gulu, however, is connected to Uganda's capital by a paved highway, and flights from the now-prospering Kampala depart daily to London, Paris, Johannesburg, Nairobi and other African locales. The threat of spread in this case is a bit more real.

In Washington top national security leaders, both in the White House and at the Central Intelligence Agency, fret continuously about such things. There is genuine fear that the U.S. will be caught off guard by a dangerous microbe. After all, it's happened before; many times, most notably with HIV and hepatitis C. There is a tendency in such circles to seek high-tech solutions in the form of microbe sensors and automated early-warning systems.

But the reappearance of the Ebola virus does not signal such a need. Rather, it is warning us that we ignore the essential public health needs of the world's poorest nations at our own peril. Unless the wealthy world is prepared to assist in the development of strong infrastructures in the poor world, microbial diseases will remain a threat to us all. Investment need not be prohibitively massive. The good news is that most public health interventions are pretty cheap, and highly cost-effective.

But nobody in America ought to rest easy, thinking that Ebola, HIV, hepatitis C, malaria and other scourges that now claim record numbers of people worldwide are "over there"--not here. As long as health care workers "over there" are reusing non-sterile syringes and medical equipment, have no rapid way of contacting international or even national health authorities, lack basic laboratory diagnostic capacities and are overwhelmed by an astonishing array of background diseases that sap the time and intellectual stamina of their staff, nasty microbes will continue to break out. And, as happened with HIV, eventually something "over there" will find its way over here.

Laurie Garrett is a reporter for Newsday and the author of Betrayal of Trust: The Collapse of Global Public Health. She was awarded the Pulitzer Prize for coverage of the 1995 Ebola outbreak in Kikwit, Zaire.