A seven-year-old boy infected with the H1N1 virus has died marking Sweden's first death linked to swine flu this season, a health official was quoted as saying Saturday.

The boy was one of three patients being treated at different intensive care units in the southern Swedish region of Scania for H1N1 and died in Helsingborg Friday, said Per Hagstam of the Scania division of the Swedish Institute for Infectious Disease Control (SMI).

"What (the three) had in common was that they all belonged to the risk group and had for instance other types of complicated illnessess," Hagstam told the local daily Helsingborgs Dagblad.

By December 26, 65 people in Sweden were known to have contracted H1N1, which killed 30 Swedes during the last flu season, according to SMI.

The World Health Organisation declared the swine flu pandemic over in August, more than a year after the virus that emerged from Mexico sparked panic and killed thousands of people around the world before fizzling out.