First Imported Lyme Disease Case in 2025: 60-year-old Woman Infected in Sweden Returns to Taiwan

Epidemic Prevention Physician Lin Yung-ching of the Ministry of Health and Welfare's Centers for Disease Control (CDC) explained at today's regular epidemic weekly report that a woman in her 60s from northern Taiwan, with a history of hyperlipidemia, had been living in Sweden since May 2024. She reported engaging in forest activities near her home and being bitten by insects. On March 10 this year, she sought medical attention at a local hospital due to itchy skin symptoms. As Lyme disease is prevalent in temperate regions, the local physician was alerted, diagnosed her with Lyme disease, and prescribed antibiotics.
Lin Yung-ching pointed out that the case entered Taiwan on March 17. Subsequently, due to hematuria symptoms and persistent skin symptoms, she sought medical attention at a hospital on the 18th and 25th, respectively. After re-testing and notification by the hospital, the infection with Lyme disease was confirmed. The infection site was determined to be Sweden, and she is currently recuperating at home.
Lyme disease is distributed in the United States, Canada, Europe, and neighboring China, Japan, and South Korea. Lin Yung-ching said that Taiwan is not an endemic area, and past cases have all been imported. It is transmitted by infected hard ticks (commonly known as dog ticks) and is not transmitted from person to person. Infection usually occurs during outdoor activities or through pet ownership, after being bitten by a tick.
The incubation period for Lyme disease is 3 to 30 days (average about 7 days). Lin Yung-ching pointed out that in the early stage of infection, symptoms similar to a cold may appear, such as headache, fever, chills, nausea, vomiting, muscle pain, and swollen lymph nodes. More notably, 70% to 80% of cases will develop "erythema migrans," where a red rash appears like a bull's-eye and gradually expands outwards. It usually requires at least about 14 days of antibiotic treatment.
More troublesome, Lin Yung-ching said, is that even if erythema migrans is not treated, it will disappear on its own within 3 to 4 weeks, but this does not mean recovery. Instead, joint pain, or heart and nervous system abnormalities may appear several weeks to several months later. More frighteningly, some patients' illness may drag on for several years, potentially causing complications such as meningitis and pericarditis. Prevention mainly focuses on avoiding tick bites.
Li Chia-lin, Deputy Director of the CDC's Epidemic Command Center, pointed out that since Taiwan listed Lyme disease as a Class IV communicable disease in 2007, there have been a cumulative total of 21 confirmed cases (ranging from 0 to 3 cases annually), all of which were imported cases. The United States accounted for the most cases with 13, with the rest from European countries such as Sweden, the United Kingdom, and France.
CDC spokesperson Tseng Shu-hui reminded that the global epidemic has been rising in recent years, and its geographical distribution has significantly expanded. The United States reported at least 89,000 cases in 2023, with a trend of geographical spread from the northeastern part of the country to the southern regions. Europe reports an average of about 132,000 cases annually, mainly distributed in Northern, Eastern, and some Western European countries. In Asia, South Korea and Japan both reached new highs in cases in 2023, with cumulative totals of approximately 39 and 18 cases, respectively, in 2025. (Editor: Li Heng-shan) 1150407