The deaths of three people who contracted listeria infections while at the Royal Group of Hospitals is not just a rare event. It is a troubling one.
The hospital has not given details of who the 'victims' are — but, needless to say, they were much-loved members of families who have now been left to grieve after a devastating loss.
Royal chiefs have said all three fatalities were patients aged between 66 and 76 who had 'life-limiting illnesses'. What they mean is that they were suffering from cancer or some other terminal disease.
These three people went in to hospital for treatment to either cure their illnesses, or at least improve their quality of life. Instead, they died after contracting a food poisoning bug probably acquired in the institution that was meant to care for them.
Listeria is a danger to older folk, and to people, including children, with weakened immune systems. Pregnant women are also particularly vulnerable. The implications for the Royal, Royal Maternity and Royal Children's hospitals are therefore potentially grave, particularly if the listeria bug travelled through the hospital's catering or retailing systems.
Clearly, the Royal's investigation must be exceptionally rigorous, and its results should be made public for external independent scrutiny.