Bartonella henselae is a causative agent of cat scratch disease in Australia

We report the first isolation of Bartonella henselae from the blood and fleas of a cat of a patient with cat scratch disease (CSD) in Australia. A 49-year-old man presented with a history that 3 weeks after he had removed fleas from his cat he had developed fever, lethargy and anorexia for 3 days. This was followed by the appearance of axillary lymphadenopathy. There was no history of a bite or scratch and no primary lesion on the skin. Two fine needle aspirates of the axillary lymph node showed granulomatous lymphadenitis with no organisms seen by Warthin-Starry silver staining or electron microscopy. No organism was cultured from the patient's lymph node aspirates or blood cultures processed by lysis centrifugation. However, the polymerase chain reaction (PCR) using p24E and p12B primers gave a 280 bp band indistinguishable from Bartonella henselae when using DNA extracted from the lymph node aspirates and the patient's blood leucocytes. DNA sequencing of the PCR product from the patient's blood showed that the DNA was from Bartonella henselae. The patient's serum had a titre of 1024 in an indirect immunofluorescence antibody test for Bartonella henselae. Bartonella henselae was subsequently cultured from fleas and blood taken from the patient's cat. This case provides evidence that Bartonella henselae is a causative agent of CSD in Australia and supports a possible role for fleas in transmission of the disease.