Swine flu mortality impact revealed
A study of the first wave of swine flu infection in the UK reveals that the disease, although mild for many, is associated with high mortality in severely affected people.
Data collected between May and September 2009 as part of the Influenza Clinical Information Network Surveillance Programme also show that severe H1N1 infection affects not only the old and the sick but also, and more commonly, generally healthy individuals.
Of the 631 study participants admitted with swine flu to 55 hospitals in 20 cities or towns, 55% had no underlying conditions, and of all in-hospital deaths from swine flu, 59% occurred in generally healthy individuals. Individuals, aged 65 years or older, made up just 5% of admissions.
The research, published in the journal Thorax, shows that 13% of patients admitted to hospital with H1N1 infection were transferred to high dependency or intensive care units (ICUs), and of these 5% died.
Co-author Professor Openshaw, from Imperial College, London, UK, told MedWire News that this 40% death rate among patients admitted to ICUs "is very high considering these included healthy or near healthy young people".
Pregnant women and toddlers were confirmed as being at increased risk of severe disease, but the findings also highlighted that mild asthmatics, and not just those taking steroid medication, were vulnerable.
Professor Openshaw said that this "justifies focusing vaccination and early treatment with antivirals on patients with asthma even if they have mild asthma."
He also noted that fever was a presenting symptom in only one in four adults and children, and suggested that it is "not a necessary part of the diagnostic algorithm."
GP News is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
By Lucy Piper