The health authorities on Tuesday confirmed the nation’s first infection with a fatal tick-borne virus that killed more than 130 people in China and Japan in recent years.

The Centers for Disease Control and Prevention reported that a 63-year old woman died in August from severe fever with thrombocytopenia syndrome or SFTS.

The virus is spread by ticks, and causes fever, vomiting and platelet and white blood cell levels to drop. The virus can also cause multiple organ failure and death.

She was bitten by insects in July while working in a field in Gangwon Province. She was hospitalized on Aug. 3 with fever and diarrhea, and died on Aug. 12 from multiple organ failure.

It is one of five suspected SFTS cases studied by the CDC. No evidence of SFTS virus infection was found in the other four cases., it said.

Health officials are looking into an additional five possible infections including a case on Jeju Island. A 70-year-old man died on the southern island on May 16 and it is considered highly likely that the SFTS virus was the cause.

According to the CDC, genetic materials indicating SFTS infection have been found and the National Institute of Health is currently trying to isolate the virus.

The CDC said that the fatality rate of SFTS virus infection appears to be much lower than earlier estimates citing data provided by the Chinese authorities.

According to the data, 2,047 people had been confirmed to have been infected with the virus over a period of two years at the end of last year. Of the total, 129 people died due to the infection, putting the fatality rate at about 6 percent. Earlier estimates had put SFTS fatality rate at about 30 percent.

Regarding the figures from Japan, where eight of the 15 confirmed cases have resulted in death, the CDC said that there is insufficient data to accurately estimate the fatality rate.

Seoul National University professor Oh Myung-don, who took part in the study, also said that the probability of contracting SFTS is low as only a small percentage of ticks in the wild carry the virus.

“The proportion of ticks carrying the virus is lower than 0.5 percent, and being bitten by a tick does not mean that SFTS virus infection will occur,” Oh said at a press briefing on Tuesday. He added that although there is no anti-viral treatment for SFTS, other methods such as platelet transfusion and dialysis can be used to treat patients.

By Choi He-suk  (cheesuk@heraldcorp.com)