Prosecution opens
From Mark Dowling at the Chester Standard
Prosecuting, Nicholas Johnson KC said everyone should be aware of the city of Chester, and its busy general hospital. Said hospital includes a neonatal unit, caring for premature and sick babies.
"It is a hospital like so many others in the UK," he added. "But unlike so many others, within the neonatal unit, a poisoner was at work."
The statistics of the mortality rate were comparable, prior to January 2015, but there was "a significant rise" in the number of babies dying or having "catastrophic collapses".
This rise was "noticed" and the concern was the babies had died "unexpectedly", and when babies collapsed, they did not respond to sufficient resuscitation.
The collapses "defied" the expectations of the treating doctors.
Usually, when an intervention is taken, a positive reponse can be expected, he told the jury.
Babies "who had not been unstable at all" or "on the mend", "suddenly deteriorated", "for no reason at all".
Consultants noted there was "one common denominator" - the presence of neonatal nurse Lucy Letby.
There were between 25-30 nurses and 15-20 nursery unit nurses in that part of the hospital, working day/night shifts. More would work on the day than the night shifts, typically.
Parents tended to visit their sick children during the day, Mr Johnson added.
Many of the events occurred "during the night shifts".
When Letby was moved to the day shifts, the rate of collapses "shifted to the day shift pattern".
Police were then called in, and commissioned a "painstaking review" by "experienced doctors with no connection to the Countess of Chester Hospital".
The review concluded that two children were "poisoned" with insulin.
The prosecution say the "only reasonable conclusion" is the babies were poisoned "deliberately - these were no accidents".
The prosecution say other collapses could be due to "sabotaging".
The prosecution adds these deaths and non-fatal collapses were deliberate, and Letby was the "constant malevolent presence" when things took a turn for the worse in these 17 children, Mr Johnson added.