It comes as health secretary Humza Yousaf warned the next few weeks will be among the “most difficult the NHS has ever faced” with widespread staff absences, rising Covid hospitalisations and soaring case numbers.
One under-pressure Scottish health board has appealed for families to help by bringing patients no longer receiving treatment home while care packages are arranged.
Opposition politicians once again called on the First Minister to reduce the self-isolation period from ten to seven days, as has been done in England, Wales and Northern Ireland to relieve staffing critical pressure.
Some 17,259 new Covid cases were reported on Tuesday, the second-highest figure after a record of 20,217 the day before.
The number of people in hospital with Covid has risen by 116, to 1,147. Further detail on hospitalisations, as well as updated figures regarding the Omicron variant, are set to be published on Wednesday as the Scottish Parliament is recalled virtually.
Boris Johnson announced on Tuesday evening that around 100,0000 critical workers in England will be supplied with daily lateral flow tests from January 10 in a bid to slow the spread of the virus. No similar scheme has been outlined in Scotland.
As new Covid cases across the UK exceeded 200,000 for the first time, the Prime Minister did not introduce any further restrictions, and said England has a chance to “ride out this Omicron wave without shutting down our country once again”.
The Scottish Conservatives urged the First Minister to reduce the self-isolation period to seven days if a person has tested negative twice, and to remove the need for household contacts to self-isolate if they receive a negative PCR test. As Scottish schools begin to return after the holidays, experts said a rise in cases was “almost inevitable”.
"Scotland has the strictest self-isolation rules anywhere in the United Kingdom,” said Conservative leader Douglas Ross.
“We understand the need for caution, but Nicola Sturgeon’s dithering and delaying is continuing to have a major impact on frontline services and the wider economy, due to the sheer numbers having to isolate.
“She must finally confirm in her latest update that the period of isolation will be cut to seven days, for those who have tested negative twice.
“Her indecision, coupled with new restrictions, has harmed many businesses at what should have been their busiest time of the year.”
He added: “Nicola Sturgeon must listen to the warnings from many crucial sectors and finally implement a cut in the length of time people have to isolate for. We’ve seen Wales and Northern Ireland now do this, so people have rightly been asking why has the First Minister continued to wait to do likewise in Scotland?
“Her current approach is unsustainable and tomorrow’s update must finally bring in the necessary changes to protect essential services.”
Scottish Labour’s Jackie Baillie also called for the rules to be changed.
“Cases have risen dramatically in the last week, but thankfully so far the rate of new hospitalisations and people with Omicron in ICU remains low,” she said.
“But despite this positive news, the picture for our public services and businesses remains bleak. The number of staff absences from the NHS and social care is very high and this is having more of an impact on services.
“The SNP must use this update to confirm whether they will change self-isolation requirements in line with the latest evidence, to stop staff absences piling yet more pressure on businesses and services this winter.”
Deputy First Minister John Swinney said on Tuesday that the Scottish Government was still “considering" a change to isolation rules.
“The First Minister confirmed that to Parliament in the virtual session on the December 29 and further details will be shared with parliament in its virtual session tomorrow,” he said.
“So, yes, that issue is under consideration. We are obviously looking at the clinical advice that is crucial in the handling of this because, as I’ve indicated before in these discussions, we do not in any way, shape or form serve anybody’s interest if we ignore the clinical dimension of this issue, and the risk of transmissibility of allowing individuals to return to the workplace if they’re still carrying the virus.”
Some unions, including the Royal College of Nursing and teaching union the Educational Institute of Scotland, have called for the self-isolation period to remain at ten days to protect workers.
Covid-related staff absences have been reported across all sectors, and are at their highest since March in the NHS, despite self-isolation exemptions for healthcare workers.
NHS Lanarkshire, which is understood to be one of the health boards under the most acute pressure, warned that its hospitals are “exceptionally busy” and asked relatives to help by bringing home patients no longer receiving treatment.
"We recognise that not all families will be in a position to do this, but we are asking families with relatives in hospital who are no longer receiving treatment to consider bringing them home where appropriate to help ease current pressures,” the health board said in a statement.
The UK Health Security Agency (UKHSA) has advised that a seven day isolation period, combined with two lateral flow tests on days six and seven, has “nearly the same effect” as a ten day isolation period without testing.
The agency predicts that after ten days of isolation five per cent of people will still be infectious, and this will be the same for seven days with testing.
Without testing, modelling suggests that after seven days 16 per cent people people would still be infectious.
The figures published by the Scottish Government on Tuesday show 56,290 new tests for Covid-19 reported results and 35.3 per cent were positive, a marginal increase from 34.9 per cent on Monday.
The figures include a note advising of delays in between tests being taken and results being reported but saying Public Health Scotland is monitoring the situation.
A total of 4,384,343 people have received their first dose of a Covid-19 vaccination, 4,022,821 have received a second dose, and 3,006,133 have received a third dose or booster.