Dean of the School of Public Health at Allegheny University in Philadelphia, Mann was an authority on AIDS, and among the first to predict that HIV would reach epidemic proportions in the developing world. His wife was head of the Center for Immunization Research at Johns Hopkins University School of Hygiene and Public Health in Baltimore, where she specialized in research into vaccines.
Both were 51, and died in the Swissair flight 111 crash off the Canadian coast September 2.