Tick-borne Disease SFTS: Misdiagnosis as a "Cold" Due to Complacency and Rapid Progression to Severe Illness

In recent years, Japan has seen a series of reported deaths from Severe Fever with Thrombocytopenia Syndrome (SFTS), a disease transmitted by ticks. In early July 2025 alone, fatalities were confirmed among the elderly in several prefectures, including Aichi, Shizuoka, Kagawa, and Miyazaki, with a high mortality rate of 10-30%. The initial symptoms resemble those of a cold, such as fever, fatigue, and vomiting, making it easy to overlook if patients do not report activities like "outdoor grass cutting" or "mountain climbing" when seeking medical attention. The Aichi Pest Control Association warns that a lack of awareness regarding tick bites could lead to a misdiagnosis as a common cold. The Ministry of Health, Labour and Welfare recommends wearing long sleeves and pants, using insect repellent, bathing, and conducting a full-body check after returning home. They urge individuals to inform their doctors of any outdoor activity history during a fever and to undergo testing. This article systematically explains the basic knowledge of SFTS, case studies, diagnostic challenges, preventive measures, medical systems, and advice for travelers, making it accessible to foreign residents and visitors in Japan. It also analyzes future risks in the context of Japan's climate change and aging population.