Australian Flu Hits the Northern Hemisphere.
by Rob Lambkin-Williams, hVIVO and Alex Mann, hVIVO
How bad was Ozzie Flu?
The Australian government has released the most recent report on the outbreak of influenza in the country (http://www.health.gov.au/flureport). The 2017 influenza season was the worst since the 2009 pandemic, more than twice the number of people were admitted to hospital with influenza than is typical. Although more people were infected, the virus itself, was not believed to cause more severe illness and the most common virus was influenza A(H3N2), particularly amongst the elderly.
There have been a higher number of deaths this year, which is consistent with the high number of cases in the community. The estimated effectiveness of the 2017 seasonal influenza vaccine was low for influenza A(H3N2), which was the most common virus in circulation throughout the season. The estimated effectiveness for other viruses circulating to a lesser extent was moderate.
The reason for the low effectiveness of vaccine was believed to be two-fold. Firstly, the vaccine produces a weaker immune response generally in the elderly, a group hit hard by the outbreak.
Secondly, this year the influenza A(H3N2) virus seemed to mutate (drift) and general vaccine protection was less across the community as a whole.
However, annual influenza vaccination is still the most important measure to prevent influenza and its complications. While in some cases, influenza vaccination may not prevent a person developing the disease, it can help to reduce the severity and/or duration of the disease and potentially prevent further serious complications. It will be important to determine going forward the proportion of the population that became infected, developed symptoms, but had only mild disease.
In the Northern Hemisphere: CIDRAP
The Center for Infectious Disease Research and Policy (CIDRAP) from the University of Minnesota, has the latest news regarding the current northern hemisphere influenza outbreak.
Last week they reported that Flu counts jumped as 46 states report widespread activity up from 36 states in the preceding week, with the H3N2 strain predominate, which is generally regarding to cause most severe illness.
Specifically, they reported “Hospitalizations due to ILI also rose this week, from 8.7 hospitalizations per 100,000 population to 13.7. Adults over 65 were most likely to be hospitalized, with 56.6 hospitalizations per 100,000 population, followed by adults aged 50 to 64 (15.4 per 100,000 population) and children aged 0 to 4 years (9.9 per 100,000 population). The vast majority (90.1%) of hospitalizations were associated with influenza A.”
Public Health England
Public Health England (PHE) issued their weekly reports;
They reported that;
- Flu continued to increase (compared to the peak week last year) with:
- Almost four times as many hospilisations
- Almost 50% more hospital admissions
- Increases in GP, A and E attendance and calls to the NHS helpline (111) notably higher and above that normally expected at this time of year.
- RSV continued to decline:
- RSV incidence has continued to decline from its peak in week 46, and is not at 60% of those level
The report included the following Figures which showed the sharp spike in influenza like illness and pneumonia. Figure 8 in the report clearly showing that rates of influenza are “very high” compared to previous years.
There were 141 new acute respiratory outbreaks reported in week 52, compared with 34 in the preceding week. Influenza-confirmed hospitalisations in week 52 was 6.82 per 100,000 population, compared with a much lower figure of 2.33 per 100,000 in the previous week. Both Influenza A and B were circulating. RSV activity was declining.
Lastly, RSV continues to decline from peak. All other viruses are low including HRV as show in Figures 12 and 13 from the reports.
Please read the report in full using the links above.
The UK Flu Survey
The UK flu survey, provided a fascinating insight into the distribution of the virus across the UK. A collaboration between PHE and The London School of Tropical Medicine, it is updated every three minutes. Flu survey is an online survey that monitors trends of flu like illness in the community. It is open to any member of the UK public to register and report flu like symptoms during the winter months. It was launched on 16th July 2009, during the swine flu pandemic, and is part of a Europe-wide initiative to monitor influenza-like illness (ILI). There are currently more than 7,500 people, participating in this survey.
A heat map of ILI can be viewed here.
The recent issues of the popular science journal, New Scientist, dedicated itself to “The Year of the Flu”
Key Stories (Click on the link to read)
- Waiting for the big one: A new flu pandemic is a matter of time
- Pandemics past: Seven times flu has become a mass killer
- Stopping the spread: What you can do to prevent flu
- Jab in the dark: Why we don’t have a universal flu vaccine
As predicted (click here) the outbreak of influenza in Australia has spread to the northern hemisphere and the incidence of ILI is high across the USA and EU, placing strain on the national health services of many countries. The need for an improved influenza vaccine in the elderly is clear, and research to develop a so called universal influenza vaccine, a vaccine that provides better protection against drifted variants of the virus between seasons, or even pandemic strains, needs to accelerate, it is clear this is a major unmet medical need.