Identification of the agent of Southern Tick Associated Rash Illness

ABSTRACT Southern Tick Associated Rash Illness (STARI) is febrile illness that occurs following bites of Amblyomma americanum ticks. Although it was initially reported over two decades ago, the agent of STARI remains unknown, and no diagnostic tests are available. The recent northward expansion of A. americanum has brought these ticks into areas highly endemic for Lyme disease. The primary indicator of STARI is an expanding rash around the tick bite, that can be misdiagnosed as an erythema migrans. The similarity of the rash and the accompanying non-specific symptoms presents challenges for physicians. In addition, there is a lack of defined treatment protocols for STARI. While it has been suggested that antibiotic treatment may have utility, this has not been clearly demonstrated. The identification of the STARI agent would have profound effects on the ability to diagnose and treat this syndrome, as well as clarify the epidemiology of this illness. In this proposal, we will employ state of the art molecular and serologic tools to identify the agent of STARI. We will identify unique microbial sequences through comprehensive metagenomic sequencing of skin biopsies taken from within the STARI rash and attached ticks. We will then develop serologic assays to demonstrate exposure to this agent in sera from STARI patients. This work will determine the microbial origin of STARI and enhance opportunities for accurate diagnostics and therapy.