It's official. Influenza, commonly known as "the flu", has reached Denmark.

"We've been waiting for it since Christmas as it has been well underway in Western and Central Europe. Fortunately, Denmark has been spared until now," Tyra Grove Krause, a senior physician at the State Serum Institut (SSI), told Politiken. 

Although, the virus has been largely absent in Denmark throughout the winter, in the past three weeks, more and more people have tested positive. 

More people have been affected by the virus now than at the same time last year.

Children and the elderly are at risk
Still, the current situation is far from the severe epidemics that ravaged Denmark in the winters of 2009-2010, 2010-2011 and 2012-13. 

According to SSI, three weeks of continuous increase in the number of infected people means more are expected to get ill in the next few weeks.

"Especially children under age five and the elderly can be hit severely," Krause noted.

Influenza virus type A H3N2
Europe has been plagued by the influenza virus type A H3N2 that mainly targets young children and people over the age of 65.

In several European countries, the authorities have already reported increased mortality rates among the elderly as a direct result of this type of virus.

SSI has reported that it is precisely this type of influenza that people are being infected by in Denmark.

A vaccine may not help this time
Krause explained that the usual vaccine will not protect people as effectively against this type of virus, which may explain the higher mortality rates in some European countries.

She believes, however, that getting vaccinated is not a waste of time, as it would protect people against other types of influenza.

During week seven, a total of 662 patients were tested for flu, of which 24 percent were positive.

That is far from the 51 percent positively tested in the rest of Europe.  

Wash your hands and stay home
Nevertheless, Krause recommends that people wash their hands frequently, sneeze into their sleeves and stay home when ill.

"When there is a flu in circulation, we don't need heroes who go to work despite fever and illness. You would do a great disservice both to yourself and to your colleagues," Krause commented.

So far, a total of 13 Danes have received intensive hospital care because of influenza this season. 

All of them had an underlying medical condition that increased the risk from serious influenza.