Disruption was largely around the central belt, with services to and from Glasgow seeing the most cancellations and delays.
ScotRail said 50 staff were now self-isolating – up from 38 last week.
The Glasgow to East Kilbride service was reduced to one train an hour, as has the Glasgow to Paisley Canal service.
Meanwhile, the Glasgow to Ardrossan Harbour and Kilmarnock/Ayr to Stranraer services were also suspended, with passengers advised to use local bus services.
The Glasgow to Kilmarnock service experienced major disruption and travellers on this route were also been urged to use local buses where they are running.
Nicola Sturgeon announced on Friday in a coronavirus briefing that all household contacts of a positive coronavirus case would have to isolate for 10 days – as of today – despite their vaccination status, and even if they have an initial negative PCR test.
During the briefing, she confirmed that 60 ScotRail services had been cancelled due to staff having to isolate, and the company has now confirmed the figure is even higher.
So far, around 150 services have been cancelled due to staff either testing positive or coming into close contact with a positive case of coronavirus.
David Ross, ScotRail communications director, said: “We’re sorry to our customers who are being inconvenienced as a result of an increase in the number of our staff self-isolating due to Covid-19.
“We are working flat out to run a safe and reliable railway in difficult circumstances.”
Customers have been advised to check their journeys before heading to the station to ensure their trains have not been impacted by the disruption.
Ms Sturgeon said on Friday the Scottish Government will “consider its next steps very carefully” in the wake of the new Omicron variant spreading given the potential economic harm that could be caused by more restrictions.