The Vale of Leven Hospital Inquiry, which is investigating the circumstances surrounding an outbreak of clostridium difficile, heard how one ward was closed three times due to a suspected outbreak of norovirus.
Sister Anne Madden was senior charge nurse of Ward 15 during the C.Diff outbreak.
On her first day of evidence it was revealed the rehabilitation area for up to 24 patients was shut on three occasions between December 2007 and January 2008 as patients showed norovirus symptoms.
The ward was then also caught up in the C.Diff outbreak which affected 55 people, killing 18, between December 2007 and June 2008.
Sister Madden was asked to look at medical records for patient John Boyle, who died in Ward 15 in February 2008 at the age of 90.
Although he had diarrhoea and suspected C. Diff, he was not isolated until after C.Diff was confirmed by the lab – despite an NHS Greater Glasgow and Clyde policy recommending isolation for any patient "who could contaminate the environment with faeces".
Colin MacAulay QC, senior counsel to the inquiry, asked why Mr Boyle was not isolated sooner.
Sister Madden said: "If the dates I have are correct, the ward was actually closed from 15 to 25 January with norovirus. So during those circumstances, due to the numbers, it can be quite difficult to isolate everybody who is symptomatic.
"Norovirus quite often sweeps a ward."
It was also revealed during Sister Madden's evidence that medical records in relation to Mr Boyle's treatment were not properly completed by nurses on Ward 15.
A document known as a Falls Risk Assessment was started for Mr Boyle on January 13, 2008 and concluded he was at "very high risk" of falling.
A review of his risk of falling was scheduled for a week later, but never carried out.
A nutritional screening tool was also not properly filled in.
It contained only his name and initial weight and was otherwise blank, while separate nursing records showed Mr Boyle had lost around 2kgs in weight over a few weeks.
Asked to explain, Sister Madden said: "There is usually always another task to be completed, and unfortunately if you don't get the opportunity to complete the documentation at the time, it is difficult to sometimes find the time to go back."
The inquiry, before Lord MacLean at Maryhill Community Central Halls, continues.