Q fever in California. VII. Clinical features in one hundred eighty cases.

Q FEVER was originally described by Derrick 1 in Queensland, Australia, where it was first observed as an acute febrile illness among abattoir workers. Since 1945, the disease has been reported from many parts of the world 2 and from a number of widely separated localities of the United States. 3 At present the disease appears to be established endemically in California, where in the past three years more than 700 cases have been recognized and confirmed in the laboratory. In certain parts of the state this disease has become an important addition to the differential diagnosis of acute febrile illnesses. The disease is caused by a Rickettsia, previously known as Rickettsia burneti or Rickettsia diaporica, but now designated as Coxiella burnetii (Derrick). The genus Coxiella has been chosen because this organism differs from other members of the rickettsial group in several important respects, e. g., the organism is filtrable,