A CASE OF CAT SCRATCH DISEASE DIAGNOSED BY INDIRECT FLUORESCENT ANTIBODY ASSAY OF IgM SPECIFIC FOR A JAPANESE STRAIN OF Bartonella henselae.

PURPOSE:To report a case of cat scratch disease-associated retinitis diagnosed with an indirect fluorescent antibody (IFA) assay for immunoglobulin M (IgM) specific for a strain (YH-01) of Bartonella henselae recently identified in Japan. METHODS:Case report of a 24-year-old pregnant woman presented with general fever, fatigue, as well as blurred vision, and a central visual field deficiency in her right eye and was suspected as cat scratch disease because she had started to feed a feral dog a month ago. RESULTS:The patient's serum tested negative, however, with an IFA assay for IgG or IgM specific for the Houston-1, common strain of B. henselae. Further testing with an IFA assay for IgM specific for the YH-01 strain yielded a positive result. On the basis of the clinical findings and the IFA results, we were thus able to make a definitive diagnosis of cat scratch disease. CONCLUSION:An IFA assay based on the YH-01 or combination of both YH-01 and Houston-1 strains of B. henselae may show increased sensitivity for the diagnosis of cat scratch disease in Japan.