Police arrest ex-nurse on suspicion of fatally poisoning patient at Yokohama hospital

YOKOHAMA -- Kanagawa Prefectural Police arrested a former nurse on July 7 on suspicion of fatally poisoning a patient at a hospital here. She has reportedly admitted to putting a disinfectant into the intravenous (IV) drip bag, police said.

"I was not very good at explaining to families what happened when patients died," the 31-year-old former nurse was quoted as explaining.

The two poisoning victims at her former place of employment, Oguchi Hospital, now renamed Yokohama Hajime Hospital, in Yokohama's Kanagawa Ward, were Sozo Nishikawa of Yokohama's Aoba Ward and Nobuo Yamaki of the same city's Kohoku Ward, who were both 88 at the time of their deaths in September 2016. The two shared the same room on the fourth floor of the facility.

Nishikawa died around 7 p.m. on Sept. 18, 2016, after an alarm went off at about 4:50 p.m. due to a low heart rate. The same happened to Yamaki two days later, with his heart rate falling at around 4 a.m. and he died roughly 55 minutes later.

After Yamaki's death, an autopsy detected a surface-activating agent in his body, and his death was ruled to be a poisoning, leading to the opening of an investigation. When an autopsy was then also carried out on Nishikawa, the same agent was also discovered inside of his body. The surface-activating agent is contained in the anti-bacterial disinfectant "Germitol."

In the fourth-floor of that wing of the hospital, bottles of Germitol at a concentration of 10 percent were kept, and around 10 of some 50 unused IV drip bags were discovered with what looked to be pinholes. The surface-activating agent was detected in a portion of those bags.

The arrested former nurse was mainly in charge of that wing of the hospital's fourth floor. She started work at around 3 p.m. on Sept. 18 and was seen entering Nishikawa's room about five minutes before the sudden change in Nishikawa's condition by a different staff member. The former nurse finished her shift on the morning of Sept. 19, and was not present in the hospital when Yamaki passed away.

However, when the Kanagawa Prefectural Police requested the clothing of the nurses and other staff members in the ward where Nishikawa and Yamaki's room was, a large amount of the Germitol was detected on the former nurse's uniform.

The former nurse told the Mainichi Shimbun in September 2017, "I don't know who did it, but I can absolutely say that it wasn't me." As the witness testimony and her clothes turning up positive for the disinfectant only constitute circumstantial evidence, police were carefully investigating the case before arresting her on murder charges.

(Japanese original by Tsumuki Nakamura and Ai Kunimoto, Yokohama Bureau)