Discovery of the relapsing fever tick (Ornithodoros turicata americanus Marx) (Acari: Argasidae) in Georgia, USA

Abstract

We report the first Georgia, USA, records for the relapsing fever tick, Ornithodoros turicata americanus Marx, a gopher tortoise (Gopherus polyphemus Daudin) burrow commensal and proven vector for human relapsing fever spirochetes and African Swine Fever Virus. During May–June 2026, we documented O. t. americanus at 14 sites (in 8 counties) located in the Atlantic Coastal Plain of southeastern Georgia. These collections extend the known range of the tick from northeastern Florida 118 km to the north. We surveyed for O. t. americanus by scooping, then sifting, sand from inside active adult tortoise burrows. At sites where we found O. t. americanus, ticks were present in 68/127 (53.5%) of burrows sampled. We collected 252 O. t. americanus comprised of 27 males, 37 females, 184 nymphs and 4 larvae. Based on negative survey data, the northern range limit for O. t. americanus are sand ridges associated with the Altamaha River. Ornithodoros turicata americanus may also occur in southcentral and southwestern Georgia, and we recommend further gopher tortoise burrow surveys targeting this tick in these regions.