Scrub Typhus With an Unknown Source of Infection

Scrub typhus, caused by Orientia tsutsugamushi, is a mite-borne zoonotic disease endemic to many parts of Asia. Although traditionally associated with rural environments, cases of urban transmission are increasingly being reported, possibly due to ecological changes such as urban heat islands, which may expand the habitats of vector mites. Recognizing these emerging patterns is important, as scrub typhus often presents with non-specific clinical features, making diagnosis challenging and potentially delaying appropriate treatment, thereby worsening patient outcomes. We report a case of an 84-year-old woman who presented with a seven-day history of anorexia, malaise, and headache. Physical examination revealed mild altered consciousness, an eschar on the left eyelid, and a maculopapular rash on the trunk. Laboratory findings included thrombocytopenia, elevated liver enzymes, and increased C-reactive protein (CRP). Despite no known exposure to grasslands or brush fields, and with no recent travel, animal contact, or other potential exposure routes identified, scrub typhus was suspected based on clinical findings. She was treated with intravenous minocycline for 14 days, following which the fever resolved and laboratory abnormalities improved. The antibody test for Orientia tsutsugamushi was positive. Her clinical course was favorable, and she was discharged in good condition. Although scrub typhus is traditionally associated with rural environments, urban transmission is becoming more recognized, possibly due to ecological changes such as urban heat islands, where temperatures are higher than in surrounding rural areas, potentially expanding the habitats of vector mites. This case highlights that scrub typhus should be considered in patients presenting with fever, rash, and eschar, even when no clear environmental exposure is identified.