SFTS infections surge to 78, outpacing last year's record pace; first cases reported in Ibaraki and Okayama

The number of reported cases of Severe Fever with Thrombocytopenia Syndrome (SFTS), a tick-borne infectious disease, has reached 78 so far this year, exceeding the record pace set last year, according to Japan's National Institute of Infectious Diseases (NIID). Seven new infections were confirmed in the week leading up to June 14, 2026, pushing the total beyond the previous year's record. For the first time in 2026, infections were reported in Ibaraki and Okayama prefectures, which had not seen any cases earlier this year.

SFTS is caused by a virus carried by ticks, primarily the Haemaphysalis longicornis species, and is transmitted to humans through tick bites. Symptoms include fever, nausea, and vomiting, and severe cases can lead to hemorrhagic fever and death. The disease has a fatality rate of approximately 10-30% in reported cases, according to the NIID.

The Ministry of Health, Labour and Welfare has warned that infections tend to increase during the fall, when tick activity is at its peak. Officials are urging the public to take precautions when entering grassy or wooded areas, such as covering skin, using insect repellent, and checking for ticks after outdoor activities. The ministry continues to monitor the situation closely, as the current surge is already outpacing the record year of 2025.