Lyme Disease in Canada

We present an uncommon case of probable Lyme disease in a neonate who developed the Jarisch–Herxheimer reaction after starting antibiotics. Lyme disease is a tick-borne bacterial infection endemic to regions of Canada, the United States, Europe and Asia. In North America, it is caused by the spirochete Borrelia burgdorferi, which is transmitted primarily by Ixodes scapularis in eastern and central Canada and Ixodes pacificus in British Columbia. 1 The incidence of Lyme disease is increasing in Canada.2 The annual number of cases reported by the Public Health Agency of Canada increased from 144 in 2009 to 2851 cases in 2021.3 This increase has been concurrent with a northward expansion of Ixodes species, possibly mediated by increasing temperatures related to climate change.2