Detection of Rochalimaea henselae in cat-scratch disease skin test antigens.

One of the diagnostic criteria for cat-scratch disease is a positive delayed-type hypersensitivity skin test reaction to an antigen prepared from purulent material aspirated from a cat-scratch disease-involved lymph node. Polymerase chain reaction coupled with DNA sequence analysis was used to identify organisms found in these skin test antigen preparations that may be responsible for eliciting this response. Two independent sources of cat-scratch disease skin test antigens yielded DNA sequences characteristic of the newly described rickettsia, Rochalimaea henselae. These results coupled with previous serologic data strongly suggest that R. henselae plays a central role in the etiology of cat-scratch disease.