Four people have died in Scotland from swine flu and another 13 have been treated in hospital after contracting the virus.
Colin Campbell from Skye was one of this winter’s fatalities.
The 52-year-old had been transferred to hospital in Glasgow after suffering from a heart attack and was found to be carrying the H1N1 strain of flu.
Health officials have refused to disclose the geographical spread of other victims.
Of the 13 people known to have been hospitalised with the virus since the end of October, at least six have been admitted to intensive care units since January 26.
Health Protection Scotland (HPS) said doctors were dealing with an “increasing number of severe cases of influenza”.
While a rising number of cases of swine flu have been reported in England, mainland Europe – particularly Greece – and in America and Canada, infection rates in Scotland currently reflect seasonal norms.
The virus was responsible for 66 deaths in Scotland during a pandemic in 2009 but the H1N1 strain has now become the most common version of flu and people are now routinely vaccinated against it.
Hugh Pennington, emeritus professor of microbiology at Aberdeen University, said better immunisation, detection and treatment of the infection since 2009 was keeping the number of seriously ill patients low.
He added: “Swine flu never went away after the pandemic and it basically became the strain of flu, replacing all the other flus that were around.
“It has been a relatively quiet season and the reason we are seeing these cases is that there was a lot of effort put into finding cases and better treatment of cases.
“What these figures show is that they are taking flu seriously. Unfortunately, every year, people do die of flu but now you can tide over patients in ICU that would have died 10 to 15 years ago.”
A six-year-old boy from Belfast was also transferred for treatment in Glasgow after being diagnosed with swine flu.
He was treated at the Royal Hospital for Sick Children at Yorkhill in Glasgow. His condition is unknown.
A Scottish Government spokeswoman said: “We welcome that levels of flu remains low overall for this time of year.”
A further six cases of e.coli linked to burgers eaten at a concert venue have been identified, taking the total number affected in the outbreak to 21.
Investigators have linked the cases to the SSE Hydro in Glasgow, with three days between January 17 and 19 as the likely infection period.