Japan is witnessing a rise in cases of a potentially fatal tick-borne disease, with infections surpassing last year's record pace, according to preliminary data from a national health research body. As of June 7, a total of 72 cases of severe fever with thrombocytopenia syndrome (SFTS) had been reported, compared with 68 during the same period in 2025, when Japan recorded an annual high of 192 cases, data from the Japan Institute for Health Security shows.
Health Minister Calls for Vigilance
Health Minister Kenichiro Ueno stated at a press conference on Tuesday that the number of patients is trending upward. "Nationwide vigilance is necessary, and we will continue monitoring the infection situation," he said. Noting that ticks are most active from spring through autumn, Ueno urged people to cover their skin when entering grassy areas and to use insect repellent on pet dogs and cats.
Transmission and Symptoms
SFTS spreads most commonly through tick bites but can also be transmitted through contact with the blood of infected people or animals. After an incubation period of six to 14 days, patients may develop symptoms such as fever, vomiting, diarrhea, and impaired consciousness. The disease is estimated to have a fatality rate of 10 to 30 percent.
Treatment and Historical Context
While there is no vaccine for SFTS, an antiviral drug has been approved in Japan. The country confirmed its first SFTS case in 2013 in a woman in Yamaguchi Prefecture, western Japan. Annual case numbers generally remained below 100 until 2021 but have exceeded that level every year since. More SFTS cases have been reported in western Japan than in eastern parts of the country.
