Fears over ‘biggest medical cyber-attack in history’: IT system that holds hospital records of 20million Americans is hit causing cancer delays and ambulance diversions

• CommonSpirit health has admitted to suffering ‘IT issues’ due to a cyberattack
• The fourth largest health system in the country is facing disruption in units
• It was not clear how many of the 140 hospitals across 21 states are affected 

The medical records of up to 20million Americans may have been leaked in what could turn out to be the biggest medical cyberattack in US history.

CommonSpirit Health — the fourth largest health system in the country — was the target of a major IT ransomware attack this week.

It is not clear how many of the 140 hospitals across 21 states are affected, but the hack has already led to cancer appointments being cancelled and ambulances diverted.

Among those affected are the Virginia Mason Medical Center in Washington — the second best in the state — and MercyOne Medical Center in Iowa.

IT experts today warned it may be the ‘biggest’ ever to cyber attack on a medical system in the US.

A CommonSpirit spokesman admitted this week that electronic health records — which hold patient data — and other systems had been taken offline.

They added: ‘As a result of this issue [the IT attack], we have rescheduled some patient appointments.

‘Patients will be contacted directly by their provider and/or care facility if their appointment is impacted.’