Malcolm J. Casadaban, a molecular genetics professor at the University of Chicago, died last Sunday, seemingly from an infection of a weakened form of Yersinia pestis, the bacteria that causes the plague
. "Because this form of the bacteria is not known to cause problems in healthy people, special safety procedures are not required to handle it, said Dr. Kenneth Alexander, a virologist and chief of pediatric infections at the U. of C. Medical Center. Lab researchers who work with the bacteria would typically wear gloves, a lab coat and protective goggles, and the bacteria would be disposed of in a biohazard bag and heated for about two hours, Alexander said. Two key questions in Casadaban's death will be whether there was anything different about the strain of bacteria he was handling and whether Casadaban had any underlying conditions that may have made him more susceptible to infection."