From Q for query, because the disease was an illness of unknown etiology. In 1937, Australian researcher Edward Derrick reported a disease that affected workers in slaughterhouses. Coxiella burnetii, the bacteria that causes the disease, was found shortly after Derrick’s investigation began. However, many aspects of the disease continue to puzzle researchers, making the name Q fever as appropriate today as it was 74 years ago.

Sources: Cooke RA. Q fever. Was Edward Derrick’s contribution undervalued? Med J Aust. 2008;189:660–2. PubMed; Derrick EH. “Q” fever, a new fever entity: clinical features, diagnosis, and laboratory investigation. Med J Aust. 1937;2:281–99; Dorland’s illustrated medical dictionary. 31st ed. Philadelphia: Saunders; 2007; Mackerras IM. Australian Academy of Sciences biographical memoirs of deceased members: Edward Holbrook Derrick 1898–1976 [cited 2011 Sep 9]. http://www.asap.unimelb.edu.au/bsparcs/aasmemoirs/derrick.htm#mac