Pensioners, health care workers, children and people with long-term illnesses have all been urged to get vaccinated as the number of cases of individuals with flu soars.
The Health Protection Surveillance Centre (HSPC) said today that cases of influenza have risen from 72.8 per 100,000 people in the last week of December to 100.6 per 100,000 in the first week of January 2009, the highest rate seen since the 2000/2001 influenza season.
"As influenza continues to circulate in the community, it is important that people in high-risk categories get vaccinated against influenza," said HPSC specialist in public health medicine, Dr Derval Igoe.
High-risk groups include those over 65 years of age, people with chronic illness such as lung disease, heart disease, and diabetes, those with lower immunity due to disease or treatment, children on long-term aspirin therapy, health care workers and residents of nursing homes.
The symptoms of flu usually develop over a matter of a few hours and include a high temperature, sore muscles, dry cough, headache and sore throat.
The HSPC advised anyone with the flu to stay at home, rest, drink plenty of fluids and use over-the-counter remedies like paracetamol to ease symptoms. People in high-risk categories should contact their GP if they develop influenza symptoms.