Pl. spirilla. Bacteriol. [mod.L., dim. of L. spīra SPIRE sb.3] A genus or group of bacteria characterized by a spiral structure; any member of this genus, esp. the species found in the blood in relapsing fever.
1875. Huxley & Martin, Elem. Biol., 28. Spirillum. Elongated unjointed threads rolled up into a more or less perfect spiral: frequently two spirals intertwine.
1878. Bristowe, Th. & Pract. Med. (ed. 2), 134. Spirilla are moving spiral filaments of extreme tenuity.
1895. Westm. Gaz., 8 Nov., 8/1. The water used in making the creams teemed with micrococci, bacilli, and spirilla.
b. Spirillum fever, relapsing fever.
1886. Pye-Smith, Fagge’s Princ. & Pract. Med., I. 201. With the analogy of spirillum fever to guide us.
1897. Allbutt’s Syst. Med., II. 368. In spirillum fever there is no rash.
