The expected winter flu wave is hitting earlier this season.
Figures from the Federal Health Office show that last week there were 89 visits to the doctor per 100,000 inhabitants with flu symptoms – compared to 53 the week before.
The age group most affected are those aged between 15 and 29.
The number of cases is higher than the same period over the past four years.
The health office says it expects the flu epidemic to be earlier this year.