Diagnosis and control of rickettsial diseases

Abstract

Common isolation procedures on chick embryos and laboratory animals are not of great importance for routine diagnosis of rickettsioses. Detection of rickettsiae in skin lesions by immunofluorescence technique allows early diagnosis of Rocky Mountain spotted fever (RMSF). Broad spectrum of methods is at disposal for serological diagnosis of rickettsial diseases. Their choice is determined by laboratory equipment, professionality of laboratory staff, economy and simplicity of the given test. Though complement-fixation and microagglutination tests held their position and will certainly be used in future, the use of indirect immunofluorescence test is recommended for its sensitivity and simplicity. Latex agglutination test is valuable especially in the diagnosis of acute rickettsial infections. Recently introduced ELISA method is expected to fulfil the highest requirements as to sensitivity in differentiation of rickettsioses within the known classification groups. The efforts to obtain efficient antirickettsial vaccines have been limited to preparation of the vaccines against RMSF and Q fever. As to the latter, elaboration of chemovaccine and preparation of chloroform-methanol-treated phase I C. burnetii suspension of decreased reactogenity seem promising in field trials.