EIGHT hospital wards in Lothian have been closed because of an outbreak of norovirus, the winter vomiting bug.
Figures reveal the number of patients across Scotland hit by the virus has doubled in the last month.
And today Labour called on the Scottish Government to create a National Reference Laboratory to help track cases of the bug.
Latest official data shows that in the final week of last month eight wards in Lothian hospitals were closed because of norovirus, compared with just one in the equivalent week of 2008.
The previous week there had been 11 wards closed, compared with three at the same time in 2008. Only Greater Glasgow & Clyde health board reported more wards closed over the two weeks.
In response to a parliamentary question, health secretary Nicola Sturgeon revealed there were 532 confirmed cases of norovirus in Scotland at the end of December, compared with 133 in December 2008.
Edinburgh Central Labour MSP Sarah Boyack said: "I am very concerned that the number of cases of norovirus may not have peaked and this could be the worst winter we have seen for some time. I want the Scottish Government to start taking hospital infections much more seriously.
"That's why I am calling on ministers to create a National Reference Laboratory that will help us keep track of the bug. We also need a much more robust, mandatory reporting system for winter vomiting sickness."
Leading microbiologist Professor Hugh Pennington backed the call for better tracking.
He said: "The Scottish Government are again running behind England. There is real complacency here in view of the disruptive effect of ward closures caused by this bug.
There is also a growing realisation that norovirus can be fatal for those with underlying health problems.
"A National Reference Laboratory would help us follow the evolution of new strains and perhaps enable us to explain why the virus has become so common."
Alison McCallum, director of public health and health policy, NHS Lothian, said: "We have strict infection control procedures in place to contain any outbreaks within our hospitals and, as with the other health boards across Scotland, we have seen an increase in the number of incidents compared to last year."
A government spokeswoman said norovirus circulated every winter. She said: "Norovirus is highly contagious and is an unpleasant but short-lived illness. Fortunately, the vast majority of people make a full recovery with no complications.
"In 2004 Health Protection Scotland issued guidance for control of norovirus, which includes environmental cleaning, hand hygiene, isolation of patients, and restrictions on movement of staff and patients."