Concerns about a killer tick virus spread nationwide over the weekend as health authorities reported more patients who are thought to have been infected.

The Korea Centers for Disease Control said on Saturday that a 61-year-old woman in Gwangju has shown symptoms of the tick virus that has killed two people in Korea so far.

The state-run disease control agency last week confirmed that two people in Gangwon Province and Jeju died after showing signs of a high 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 tick virus has a fatality rate of about 6 percent.

Another man in Busan died after showing symptoms of the virus on Wednesday, officials said.

The Gwangju woman is suspected to have been bitten by a tick during her trip to a mountainous area in Naju, South Jeolla Province on May 17 and currently is receiving treatment. She started to vomit and had a fever a week after the trip, said the KCDC officials adding that they will trace the infection route.

The Gwangju case is the latest in a series of reports of patients suspected of having the tick-borne virus. Patients suspected of being infected with the deadly virus have been found in South and North Chungcheong Province, Gangwon and Jeju.

Amid fast-spreading fear of the virus, the government released guidelines to prevent further infection. The Ministry of Agriculture, Forestry and Food said people, particularly farmers, need to minimize skin exposure and not nap lying down in fields. The ministry also advised people to refrain from going to the toilet in hedges or other bushes and take shower immediately after spending time outdoors.

By Cho Chung-un  (christory@heraldcorp.com)