The source of an infection that contributed to the deaths of two premature babies in a hospital intensive care unit may never be known, NHS chiefs have said.
Dr Alan Mathers, chief of medicine, women's and children's services at NHS Greater Glasgow and Clyde, said the infants - whose deaths were in part due to the Staphylococcus aureus blood stream infection - had been amongst the "most vulnerable patients" in the country.
A third baby at the Princess Royal Maternity Hospital in Glasgow who also has the infection is "not giving us any cause for concern at all", Dr Mathers added.
Read more: NHS boss assures patients Glasgow's intensive care units are 'safe' following deaths of two babies
Asked if it is known how the infection started, he told BBC Radio Scotland's Good Morning Scotland programme: "Not yet and it may be that we don't ever get to the root of the problem.
"The issue is that everyone carried bacteria in their skin and are colonised by these things, that is very different from an infection.
"The premature baby has lots of systems that are just not ready for the world, including its immune system, and any breach in the fragility of these babies can lead to bacteria that would otherwise not bother us."
An incident management team has been set up to investigate the three cases of the Staphylococcus infection at the hospital's neonatal unit.
Read more: Two babies die in Glasgow's Princess Royal Maternity Hospital after infection
NHS Greater Glasgow and Clyde said in a statement the babies who died were "extremely poorly" due to their early births, with infection being "one of a number of contributing causes in both deaths".
Dr Mathers said because the infants had been born "very prematurely" there had always been "a potentially high chance of a poor outcome".
He added: "As far as neonatal intensive care goes, these are the most vulnerable patients in the NHS, full stop."
The deaths came as prosecutors continue to look at two deaths at Glasgow's Queen Elizabeth University Hospital. A 10-year-old boy and a 73-year-old woman died after contracting the Cryptococcus infection.
Read more: Crown probing second infection death at Glasgow Queen Elizabeth University Hospital
Jason Leitch, national clinical director at NHS Scotland, insisted that despite the outbreaks, the health service has infection control under control - although he stressed that would be no consolation for those who had lost loved ones.
He also said there is "no better place in the western world" for premature babies to be cared for than in Scotland's neonatal units.
Mr Leitch, also speaking to BBC Radio Scotland, said: "These units are safe and if your baby is premature and requires intensive care, this is exactly the place you want your baby to be.
"There is no better place in the western world to have your premature baby looked after than the intensive care units at Scotland."
Cases of the Staphylococcus aureus infection in the NHS in Scotland have fallen by 93% in the last 10 years, he added.
"They are rare events," Mr Leitch said.
"But the fact that they are rare events gives us all the more opportunity to learn from them and aim for zero, that would be our hope that Scotland, although leading the world in infection control, would get better still."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules here