In a letter sent out to all practices in England, DoH director of immunisation Dr David Salisbury states that the 'overall rate of influenza reports has exceeded the threshold at which the NICE guidelines on the use of antiviral drugs are triggered'.
In the first week of 2008, 31 people per 100,000 visited their GP with flu or flu-like symptoms, compared with 21 in the last week of 2007.
Consequently, the use of antiviral drugs for the prevention or treatment of influenza is now recommended, said Dr Salisbury.
At the threshold of 30 cases per 100,000 population, NICE advises oseltamivir (Tamiflu) to be prescribed for the prevention of influenza to patients in at-risk groups. The drugs should only be given if patients have not been vaccinated.
According to the HPA, the predominant flu strain circulating this year is influenza A with subtype H1, against which the current flu vaccine offers good protection.