"The discovery of a new disease is always exciting," Dr. John D. Frame told the New York Society of Tropical Medicine, "especially when it proves to be as contagious, lethal and apparently widespread as Lassa fever."
Such adjectives, coming from a Columbia University professor, sounded unscientifically hyperbolic. In fact, they represented an understatement of the facts. When Dr. Frame, an assistant professor of tropical medicine at Columbia, reported his findings late last month, Lassa fever had already proved so deadly that one of the world's most expert virologists had fallen ill of...