AIDS likely made the leap from chimpanzees to humans because of a starving World War I soldier who was forced to hunt the animals for food, according to a new book. The unknown “Patient Zero” was part of an invasion force of 1,600 Belgian and French troops who, along with 4,000 African aides, had traveled from Leopoldville in the Belgian Congo to a remote outpost in Cameroon, says Canadian microbiologist Jacques Pepin, who once worked as a bush doctor in central Africa in the 1980s. Pepin, a professor in the Department of Microbiology and Infectious Diseases at Universite de Sherbrooke...