This Dec. 17, 2017 file photo shows an intensive care unit of Ewha Womans University Mokdong Hospital in Seoul. Newsis

The Supreme Court has confirmed the not-guilty verdicts of seven doctors and nurses at Ewha Womans University Mokdong Hospital in Seoul in the case of deaths of four newborns by bacterial infection in 2017, court officials said Friday.

The top court upheld lower court sentences that found the four doctors and three nurses at the university hospital not guilty of death by occupational negligence over the deaths of the newborns, they said.

On Dec. 15, 2017, four infants died within a span of two hours while being treated in the intensive care unit of the general hospital in western Seoul. Forensic results later showed that their deaths were all caused by citrobacter freundii, bacteria which can cause fatal symptoms in immunocompromised patients, including infants.

The seven were later referred to trial on charges of death by occupational negligence.

The top and lower courts all said that the prosecution's case was based on unproven speculation, though the defendants were at fault for not faithfully fulfilling their infection control duty.

The courts also noted that the bacteria was not detected in other newborns who received the same injection, while citing expert opinions that the possibility of the dead newborns being infected by other routes cannot be completely ruled out. (Yonhap)