The latest update released by Health Protection Scotland (HPS), which monitors flu levels each winter, says that 14 patients have been admitted to intensive care units with the illness since the start of October.
Tests have confirmed that all but one was suffering from swine flu, the H1N1 virus which caused the flu pandemic in 2009-10 and now returns each year.
Graphs show the number of people turning to their GP with flu symptoms is similar to the winter of 2011-12, which was a mild year.
However, experts at HPS stress the flu season continues until May and they cannot predict whether or not the virus will take a stronger hold before then.
Dr Arlene Reynolds, senior epidemiologist for Health Protection Scotland, said: "Clinical influenza activity currently remains low overall for this time of year but there is some indication of community circulation of influenza.
"So far this season, influenza A(H1N1)pdm09 has been the predominant strain detected in laboratory confirmed influenza cases in Scotland."
Patients who are eligible for flu vaccinations, including pensioners, people with long-term health problems and for the first time, children aged two and three, are being urged to take up the offer. Just over 50% of two and three-year-olds have been protected against flu.
Dr Reynolds said: "These groups should have received their vaccine by now, but it's never too late to contact your GP to arrange for vaccination."
Details about the four patients who died from influenza have not been released but it was reported that a patient from the Isle of Skye died in Glasgow's Victoria Infirmary last week.