We collected questing Haemaphysalis longicornis ticks from southeastern counties of Pennsylvania, USA. Of 263 ticks tested by PCR for pathogens, 1 adult female was positive for Borrelia burgdorferi sensu stricto, yielding a 0.4% infection rate. Continued monitoring of this invasive tick is essential to determine its public health role.
Keywords: Asian longhorned tick; Borrelia burgdorferi; Haemaphysalis longicornis; Lyme disease; PCR; Pennsylvania; United States; bacteria; invasive species; ticks.