Differentiation of Severe Fever With Thrombocytopenia Syndrome From Scrub Typhus.

We developed a scoring system to differentiate severe fever with thrombocytopenia syndrome (SFTS) in 21 patients with SFTS and 91 with scrub typhus; it provided 100% sensitivity and 97% specificity (score > 1). Criteria included altered mental status, leukopenia, prolonged activated partial thromboplastin time, and normal C-reactive protein (1-point each).