Flu Season is Coming...

In Europe, winter – and therefore the flu season - is fast approaching. Typically, incidences of flu caused by the influenza virus begin around October, peak in February and start falling in March.

The flu season in the Southern hemisphere can often be a good indicator of the strains which are likely to be seen Northern hemisphere, and so how severe the illness may be. Influenza infections are seen in the colder months in Australia - so usually from May to October, peaking in July/August. As the season draws to a close in Australia, scientists in Europe can begin to predict what is likely to occur in the North.1 Unfortunately, this year the flu season in Australia has been much higher, with over 100,000 laboratory-confirmed cases reported so far - more than two and a half times than in the same period last year.2 This has resulted in about 100 deaths caused by the virus. 

Human influenza A and B are the main types of virus, and these are responsible for seasonal epidemics of the disease which occur every winter. Influenza-A viruses are more variable, and within this species, it is the subgroup H3N2 which has been responsible for so many deaths in Australia (81%) - especially among the elderly.

At present, it is difficult to say why the epidemic in Australia has been so bad. Australian flu vaccination rates are low, less than 10% of children this year have received the jab3However, it is also unclear how effective the vaccine has been. Whilst initial data indicates it was well matched to the circulating virusesit is known that the H3N2 subgroup in the vaccine is less effective in preventing infection due to its more frequent fractional mutation rate4. There is also the possibility that the tests being used are more sensitive, although most of the common diagnostic tools have been around in larger laboratories since 2007, so that is unlikely to be the sole reason.

There is evidence to believe that such a strong season may mean a higher than normal incidence of flu in Europe. Within EU/EEA countries, up to 50 million people a year are estimated to have symptomatic influenza, and between 15,000-70,000 are estimated to die from influenza associated causes.5 Till now however, some physicians (especially in primary care) do not test for influenza, and so may unnecessarily prescribe antibiotics. As well as having a negative impact on costs, antimicrobial resistance is a growing problem, which is why the correct diagnosis of this disease is essential.

Data from a study conducted by data information intelligence (dii) based on >1,000 interviews with GPs, pediatricians, gynecologists and urologists in primary care show different testing patterns throughout 8 EU countries. While >75% of primary care physicians order tests for influenza in Sweden, only 26% do so in France and the UK, and even fewer in Italy - with only 19% of GPs ordering the test. The average test volume per practice that tests Influenza across Europe is 100 tests per year.6 There is a variety of diagnostic tools available to detect influenza viruses. The most common can provide results in 30 minutes or less (e.g. Directgen Flu A&B from BD, “Now Influenza” Test from Binax, Quickvue from Quidel or Liat from Roche. Slowly we are also seeing molecular tests entering the scene (around 13% market share) with the potential for faster and more accurate diagnostics.

A current hurdle to increasing influenza testing is reimbursement, especially in fee based healthcare systems such as Germany, Italy or France. However, many in the healthcare sector believe that more and more patients would be willing to pay the costs out of pocket in order to ensure correct medication and avoid unnecessary antibiotics.

  1. Lewis Sanders IV. September 2017. Severe flu season anticipated for Europe, US. DW. (retrieved from http://www.dw.com/en/severe-flu-season-anticipated-for-europe-us/a-40384110
  2. Australian Influenza Surveillance Report and Activity Updates. September 2017 (retrieved from www.health.gov.au/flureport)
  3. National Center for Immunization Research and Surveillance
  4. VIDRL Victorian Infectious Diseases Reference Laboratory Search Search GOCLIENT LOGIN (retrieved from www.vidrl.org.au/surveillance/influenza-surveillance/)
  5. The flu season starts. Oct 2016. European Centre for Disease Prevention and Control (retrieved from ecdc.europa.eu/en/news-events/flu-season-starts)
  6. data information intelligence GmbH, “EU Molecular Diagnostics Report,” 2016