Swine Flu Deaths 'Less Than Expected'

New data, published today, has shown that anticipated deaths from swine flu are lower than were first anticipated.

The British Medical Journal's website, bmj.com, reveals that there were 26 deaths out of every 100,000 cases of swine flu in England (a fatality rate of 0.026%).

The authors of the research report conclude that "the first influenza pandemic of the 21st century is considerably less lethal than was feared in advance".

However, they emphasise that this is not a justification for public health inaction when death, serious illness and admission to hospital can be prevented.

The paper was published on bmj.com to coincide with the Department of Health's weekly H1N1 update, hosted by the Chief Medical Officer for England, Sir Liam Donaldson.

After the pandemic was announced, from June 2009 the Department of Health in England compelled all primary care trusts and acute hospitals to collate data on individuals who were believed to have died from swine flu.

Today's study is the first analysis of this material and includes all known deaths in England from swine flu up until 8 November 2009.

The research reveals that two thirds of the patients who died (66.7%) from swine flu would now be eligible for vaccination.

The authors said that this demonstrates the importance of getting high risk groups vaccinated.

Mr Donaldson and his team also argue that there is a case for extending the vaccination programme to the wider population given that a substantial minority (38%) of deaths occurred in non-high risk groups.

While the over 65s had less chance of contracting swine flu, the study reveals that this group were more likely to die from the disease if they developed it.

The authors argue that perhaps older people were less likely to become infected with swine flu because they had already been exposed to similar strains and that "without this previous exposure, the pandemic might have caused many more deaths in this age group".

The researchers say their fatality rate estimate compares well with the other three 20th century influenza pandemics – the rate for the 1918 Spanish flu was 2-3% and subsequent pandemics (1957-8 and 1967-8) had rates of around 0.2%.

The authors conclude that "many more patients may have died in England without the ready availability of critical care support, including mechanical ventilation".

(BMcC/KMcA)