Emergency alarms went off at a private hospital in Athens shortly after midnight on Monday when a 67-year-old patient received the wrong blood type during a transfusion.

According to reports, the nurse in charge mistakenly administered blood incompatible with the patient’s type. The error was quickly noticed thanks to the patient’s wife, who alerted staff. The transfusion was stopped after only 40 ml of the 200 ml bag had been administered.

The patient is now being treated in an ICU under close medical supervision.

Police immediately intervened, arresting three staff members — a 26-year-old nurse and two physicians, aged 32 and 50 — on charges of negligence and causing serious bodily harm.

Authorities are investigating how such a potentially fatal error occurred and under what circumstances the medical procedures failed.

The incident follows a similar case this year, when a woman received a transfusion with the wrong type of blood at the Tzaneio state hospital in Piraeus. She later died from the complications of the erroneous transfusion.