First confirmed tick-bite casualty

The disease control center yesterday reported the country had its first confirmed case of a person infected with a tick-borne virus, which can be transmitted to a human through a tick bite. The virus killed the patient.

Korea Centers for Disease Control and Prevention said yesterday that the cause of death of a 63-year-old female farmer, who died last August, was complications from the infection with SFTS, or severe fever with thrombocytopenia syndrome, transmitted through a tick bite.

The disease center said the farmer, whose identity has been withheld, was confirmed to have contracted the deadly SFTS virus after being bitten by ticks while she was working on her farm in Gangwon sometime between July and August.

The patient had a bite wound on the back of her neck.

The patient was admitted to a local hospital on Aug. 3 with a high fever of 38.7 degree Celsius (101.66 degrees Fahrenheit) and was transported to the Seoul National University Hospital on Aug. 8 after her symptoms got worse.

The farmer died four days later of multiple organ failure.

The Ministry of Health and Welfare said the exact cause of death remained unknown until the disease prevention center confirmed Monday the deadly virus was detected in the deceased’s blood specimen.

The ministry and the disease center are also looking into the case of a 73-year-old farmer in Jeju who died following symptoms similar to those with SFTS virus.

The National Institute of Health is now analyzing his blood sample. If confirmed that the man died from the SFTS virus, it will be the second such case in the country.

In an effort to assuage growing public worry over the deadly tick-borne virus, the ministry said yesterday less than 0.5 percent of ticks in the country are infected with any viruses.

Also, in rebuking earlier reports that the fatality rate of the tick-borne virus can be as high as 30 percent, the Health Ministry yesterday said the virus has a fatality rate of 6 percent.

“The reported fatality rate [by the media] of the SFTS virus going as high as 30 percent has been exaggerated,” said Oh Myung-don, professor of internal medicine at Seoul National University College of Medicine during a press briefing at the Health Ministry yesterday.

“According to a recent study by the Chinese government, among the total number of 2,047 Chinese patients infected with the SFTS virus, 129 have died, showing a 6 percent fatality rate.”

The ministry also stressed that though no vaccination treatments have been developed to counter the deadly virus as of yet, executing timely treatment such as “blood platelet transfusion or dialysis” could effectively lower the fatality rate.

The virus has an incubation period of six to 14 days until showing symptoms, including high fever, vomiting, diarrhea and multiple organ failure.

The virus is also known to cause a decrease in the number of white blood cells and blood platelets.

Ticks are widespread across Asia. Usually measuring only a few millimeters in size, an adult tick swells to resemble a blueberry nearly 1 centimeter (0.39 inch) wide after feeding.

The state-run disease control center reported earlier this month SFTS virus was found in one domestic tick species: haemaphysalis longicornis.

The ministry advised the public yesterday to wear long-sleeved shirts and avoid wearing shorts to minimize exposure to tick bites.

Japan reported its first case of SFTS virus infection in January and has reported eight bite-transmittable virus cases so far. Of the eight victims, five have died.

Officials have not confirmed if the tick-borne virus came from either Japan, China or developed domestically.

By Kang Jin-kyu [jkkang2@jkkang.co.kr]