 Looss was born in 1861 in Chemnitz, and was educated both there and in Łódź, Poland.Thereafter, he studied at the University of Leipzig, where he received a doctorate for his study of trematodes.Looss was sent by Rudolf Leuckart to Egypt to study the transmission of bilharzia, where he became accidentally infected with hookworm, and in so doing discovered the method by which the larvae penetrate the skin.