An Alternative Diagnosis: Bartonella Neuroretinitis.

dogs, other subspecies such as Bartonella vinsonii is more commonly associated with dogs. In Singapore, brown dog ticks (Rhipicephalus sanguineus) are the most common ticks found on dogs. Brown dog ticks can carry Bartonella species.5 The treatment for both Lyme disease and Bartonella infection is similar, with both organisms responding to ceftriaxone. Further laboratory investigation to rule out other infectious causes such as Bartonella should be sent for the patient. Dear Editor, We refer to the letter ‘Lyme Neuroretinitis in Singapore: A Diagnostic Dilemma’ published in the April 2012 Vol. 41 No. 4 issue of the Annals, Academy of Medicine. We propose a differential diagnosis of Bartonella neuroretinitis for the case reported. The authors described a 59-year-old Chinese man who had neuroretinitis with a macular star on retinal examination. Syphilis serology was negative. Enzymelinked immunosorbent assay (ELISA) serology for Lyme disease showed a positive IgG titre. A repeat Lyme serology showed no rising titre and a confi rmatory test using western blot was negative. The patient responded to treatment with intravenous ceftriaxone followed by oral amoxicillin. A weaning dose of oral steroid was also given for anti-infl ammatory effect. Direct questioning of the patient revealed positive contact history with his dog that had a previous history of ticks. No signifi cant travel history outside of Singapore was mentioned.