Preview An alarming new disease was first reported in mid-1993, and by late 1994, almost 100 cases had been identified nationwide. Mild prodromal flulike symptoms were followed within days by rapidly progressive respiratory illness and early death. Cooperative efforts of many agencies soon established the cause- a previously unidentified hantavirus. Thus, the disease was named hantavirus pulmonary syndrome. Dr Levy describes the outbreak and summarizes features of the syndrome and recommendations on prevention.