Hans Zinssers Zinsser (1878–1940) was an American physician, bacteriologist, epidemiologist, and writer renowned for his work in infectious diseases and immunology. A Harvard professor and a pioneer in typhus research, Zinsser made significant contributions o medical science during World War I and beyond. He was also a gifted writer, known for blending scientific insight with literary elegance, most notably in his classic work Rats, Lice and History. His legacy endures as a scientist with both a scalpel-sharp intellect and a storyteller's soul.