South Korea has reported its first case this year of Severe Fever with Thrombocytopenia Syndrome (SFTS), commonly known as "killer tick disease," prompting health authorities to urge caution during outdoor activities.
The Korea Disease Control and Prevention Agency (KDCA) said Tuesday that a man in his 70s residing in Ulsan had tested positive for SFTS. The patient visited a medical facility after developing symptoms including fever of 38 degrees Celsius, muscle pain, chills and loss of appetite following farm work in his vegetable garden. Tests confirmed the infection, and he is currently receiving inpatient treatment.
SFTS is a disease transmitted by bites from hard ticks carrying the virus, with cases mainly occurring between April and November. Within two weeks of infection, patients develop high fever along with digestive symptoms such as vomiting and diarrhea. Severe cases can progress to decreased platelet counts and multiple organ failure.
The disease has a particularly high fatality rate because no treatment or preventive vaccine exists. Since SFTS was designated a legally notifiable infectious disease in 2013, 422 of the cumulative 2,345 patients through 2025 have died, representing a fatality rate of 18 percent.
Infection risk is higher during outdoor activities such as farming, weeding and hiking. More than 80 percent of patients are aged 60 or older, with agricultural activities including vegetable garden work identified as the main infection route.
The KDCA emphasized that minimizing tick exposure is the most effective preventive measure. People engaging in outdoor activities are advised to wear long-sleeved tops, long pants, gloves and hats, and to use insect repellent. After outdoor activities, they should shower and check for ticks attached to various parts of the body, including the hair, around the ears and behind the knees.
"SFTS is an infectious disease for which prevention is most important," KDCA Commissioner Lim Seung-kwan said. "If fever or digestive symptoms appear within two weeks after outdoor activities, patients should immediately visit a medical facility for examination."
