physician who, in collaboration with an English colleague, Arthur W.M. Ellis, discovered the Swift-Ellis treatment for cerebrospinal syphilis ( paresis), widely used until superseded by more effective forms of therapy.

Swift specialized in the treatment of syphilis, rheumatic fever, streptococcus infections, and trench fever and served on many study commissions devoted to these diseases. He was one of many contributors to Trench Fever, a report written in 1918 for the American Red Cross Commission. Between 1914 and 1948 he also contributed articles to books on internal medicine and infectious diseases.