TAIPEI (Taiwan News) – The possibility of a stabbing victim contracting HIV was less than one in 10,000, health officials said Saturday after revealing one of the injured in the previous day’s stabbing attacks was HIV-positive.

A man identified as Chang Wen (張文) threw smoke grenades and attacked people with a knife near two Taipei Mass Rapid Transit stations and a department store. Four people, including Chang, died, with 11 injured.

One of the survivors was identified as an HIV case, Health and Welfare Minister Shih Chung-liang (石崇良) said at a news conference Saturday. As a result, the ministry had set up information and preventive medication services, per CNA.

The person in case had received long-term treatment for HIV, with his HIV viral load reduced to an undetectable level, Centers for Disease Control Director General Lo Yi-chun (羅一鈞) told the news conference.

Though the risk of infection was less than one in 10,000, the ministry still called on people who had been cut or had blood touching their eyes during Friday’s attacks to call the 1922 hotline and report to hospital for an evaluation, Lo said. If necessary, they should receive preventive medication within 72 hours to reduce the risk of infection to zero, he added.

The health official emphasized that the risk of an HIV infection was low. As an example, he said that a taxi driver transporting an injured stabbing victim in his car would not have to fear for an infection.

Lo also warned against revealing the identity of the HIV case hurt in Friday’s attacks. Doing so could incur a fine ranging from NT$30,000 (US$950) to NT$150,000, he said.

Of the 11 injured, five were still at hospitals Saturday evening, with two in intensive care and three in general wards. A Mass Rapid Transit employee was allowed to return home Saturday noon after a night in the emergency ward, the Liberty Times reported.