NARA - Severe fever with thrombocytopenia syndrome (SFTS), a tick-borne illness, is spreading across Japan with health authorities warning that infections can lead to fevers above 38°C followed by severe abdominal pain and diarrhea.
The case-fatality rate is estimated at up to 30%. Reports of new patients set a record this week, and this year has seen cases emerge in Hokkaido and the Kanto region, areas where no infections had been reported previously. Why the nationwide spread, and how should people protect themselves? Experts point to changes in human-wildlife contact and stress basic prevention.
At Nara Park, a major tourist draw, ticks can be seen on deer—on their faces, necks, and around the mouth. Local authorities are urging visitors not to touch the animals. SFTS was first identified in China in 2011, and Japan confirmed its first domestic cases in 2013. Ticks that live in grass and brush attach to passing people and animals and feed on blood, transmitting the virus in the process. Typical symptoms include a high fever over 38°C followed by intense stomach pain and diarrhea, and the illness can be fatal in roughly 10% to 30% of cases.
Cumulative infections this year reached 143 as of August 17, the highest on record, and the cumulative death toll stood at 126 by the end of August. While an antiviral drug commonly used for influenza, Avigan (favipiravir), was approved last year as a treatment option, there is still no vaccine. Officials recommend thorough use of insect repellent during outdoor activities, applied to all exposed skin.
Once concentrated in western Japan, SFTS is now being reported in Kanto and Hokkaido as well. One factor believed to be driving the spread is the growing presence of invasive and wild animals in urban and suburban environments. In a Yokohama city park, observers quickly spotted multiple Taiwan squirrels within half an hour. A nearby resident said the animals had nested in a gap under his rooftop and damaged his vegetable garden, prompting the city’s contracted pest-control team to set traps and remove the squirrels. Experts warn that species such as raccoons and Taiwan squirrels can act as carriers of ticks and increase human exposure to the virus.
The risk extends to household pets. In May, a veterinarian in Mie Prefecture who treated a cat infected with SFTS later contracted the virus and died, with transmission from the cat considered likely. With many aspects of the virus still not fully understood, specialists emphasize practical steps: avoid tick bites, refrain from handling wild or stray animals, use repellents, wear long sleeves and long pants in grassy or wooded areas, and seek medical attention promptly if bitten or if symptoms appear.
Related: Deadly Tick-Borne Virus Detected in Tokyo Dog for First Time
Source: YOMIURI
