Serological response to "Rochalimaea henselae" antigen in suspected cat-scratch disease

There are no generally accepted diagnostic tests for cat-scratch disease (CSD), the cause of which is unknown. During the development of an indirect fluorescence antibody (IFA) test for detection of antibodies to " Rochalimaea henselae", sera from patients with CSD were found to have high titres to R henselae antigens. Further tests with this assay showed that 36 (88%) of 41 patients with suspected CSD had serum titres of 64 or more to R henselaeantigen, that there was a low prevalence (3%) of substantial titres to R henselae in healthy controls (n=107), and that the immune responses to R henselae antigens were specific. These data suggest that the R henselae IFA test, or other serological assays based on R henselae, may be useful for diagnosis of CSD.