A review of the evidence in retrospect for a rickettsial etiology in Bullis fever.

The authors have presented evidence through work done 25-30 years ago for the rickettsial etiology of Bullis fever, a forgotten epidemic which occurred with over a 1,000 cases among World War II troops in training at Camp Bullis, Texas. Rickettsiae were recovered from blood and lymph nodes of patients and from ticks, Amblyomma americanum, collected in the area. All patients gave a history of tick-bites. The human and tick strains of rickettsiae, carried in chick embryo culture and in animal passage, were found to produce the characteristic syndrome of Bullis fever in human volunteers inoculated with either strain, indicating identity and specificity of infection. Wildlife in the area was found to support the stages in the life cycle of A. americanum. Deer were implicated as supporting the most abundant adult tick population, the stage which attacks man. Serologic studies eliminated othe rickettsial diseases, Colorado tick fever, dengue and many other diseases. The name Rickettsia texiana is suggested for the hitherto un-named member of the rickettsia group of organisms.