Health authorities are reminding people about personal hygiene measures like handwashing during flu season. (CBC)

Flu activity is on the rise in Britain, where it has killed 27 people since October, say health officials tracking increases across Europe.

Britain has experienced a surge in cases during December as swine flu appears to be the dominant flu strain circulating.

Britain's Health Protection Agency (HPA) said 24 people died with the H1N1 strain and three with a type B flu strain, including 10 deaths this week.

"The level of flu activity we are currently seeing is at levels often seen during the winter flu seasons, but due to the fact that H1N1 is one of the predominant strains circulating at the moment, we are seeing more severe illness in people under the age of 65 than we would normally expect," said Prof. John Watson, head of the respiratory diseases department at the HPA.

The U.K. agency noted a very large outbreak was "not likely."

Cases have been highest among children aged five and 14, followed by children under four.

"We have seen some flu outbreaks in school-aged children as well as serious cases in pregnant women. We are working throughout the public health system and [National Health Service] to protect and treat people at risk of serious illness," the interim chief medical officer for England, Prof. Sally Davies, said in a release.

Visits to doctors for flu-like illness also rose, more than doubling to 87.1 per 100,000 in the past week in the U.K. from 34.6 per 100,000, a rate that exceeds baseline levels.

More flu activity in Europe

The European Centre for Disease Prevention and Control (ECDC) said influenza transmission is now picking up across the European Union.

"During the influenza season — and especially while influenza cases are occurring in your community — citizens should adopt preventative measures recommended by their national authorities; these may include: personal hygiene measures and vaccination for those recommended," ECDC director Marc Sprenger said in a statement.

In Canada, this year's vaccine covers three flu strains: a new one known as H3N2, an influenza B component and H1N1.

Canada's flu season

Last week's influenza update from the World Health Organization also reported increased influenza activity across parts of Europe, "indicating the start of wintertime influenza epidemics in several countries.

"Influenza activity is also increasing in other temperate regions of the Northern Hemisphere, including East Asia and North America where there is evidence of the beginnings of the local winter influenza season."

In Canada, flu illness "has been geographically variable, but overall within seasonal baseline levels," WHO said.

Both the number of influenza virus detections and the proportion of respiratory specimens testing positive for influenza viruses, predominantly Influenza A(H3N2), have increased substantially in Canada, the UN health agency said.

The Public Health Agency of Canada's latest FluWatch report, posted Dec. 17, said overall flu activity in Canada increased from the previous week, particularly across the Prairies, Ontario and Quebec.

The U.S. Centers for Disease Control and Prevention said flu activity was increasing for the week ended Dec. 18 in the country. Influenza-like illness remained relatively low nationally, but is up from the previous week.