viation maps list Duar, a sprawling agglomeration of African huts, as Dwil Keil--the "lone house." In retrospect, the description sounds ominously prophetic. Located in south Sudan's western Upper Nile region, Duar found itself at the epicenter of a deadly epidemic--one of the least publicized to hit Africa in recent decades--that raged through the late 1980s and the 1990s. Of Duar's more than 1,000 original inhabitants, only four were left alive. The epidemic also took the lives of more than 100,000 people in the surrounding region.

The cause of this destruction was kala-azar (scientifically known as visceral leishmaniasis), a deadly disease caused by a parasitic protozoan. The disease is transmitted by the bite of a sand fly that is about one-tenth of an inch long and is ubiquitous in certain woodlands. Once inside the body, the kala-azar protozoan invades and weakens the immune system, causing fever, weight loss, anemia and enlargement of the spleen. If the disease is untreated, a secondary infection, such as pneumonia or malaria, usually brings painful death.

It was only the single-minded and often heroic intervention of the Dutch branch of Medecins Sans Frontieres (Doctors Without Borders) that prevented Sudan's epidemic of kala-azar from turning into a modern-day version of the black death, which ravaged Europe in the Middle Ages. MSF, founded by French doctors in the early 1970s, not only was largely responsible for bringing the epidemic under control but in the process also developed new procedures for treating the disease under extremely harsh conditions.

The driving force behind this effort was an unassuming but iron-willed American woman from Moscow, Idaho, Dr. Jill Seaman, whose previous experience had been providing public-health services to Yup'ik Eskimos in the Alaskan wilderness. In an eight-year struggle against the disease, Seaman developed a wealth of clinical expertise in treating thousands of kala-azar patients, perhaps more than any other single doctor in history.