The first official case of the winter 'flu virus has been identified - six weeks earlier than last year.
According to the National Virus Reference Laboratory (NVRL), which formally diagnoses such infections, the first case of influenza A (H3) was detected in week 46 of the year (November).
The first 'flu case in 2005 did not occur until week 52.
"The case was detected by a network of 46 sentinel general practices who report weekly on the number of patients with flu like illness," the NVRL said in a statement.
The network was set up by the Health Protection Surveillance Centre (HPSC) in partnership with the Irish College of General Practitioners and the NVRL six years ago.
HPSC director Dr Darina O'Flanagan said a total of 132 confirmed cases of influenza were detected through the network during the 2005/2006 season, peaking in March 2006.
"As we enter the flu season it is recommended that people in high-risk groups get vaccinated against influenza," Dr O'Flanagan said.
These include the over 65s, people with sever illnesses such as chronic heart disease, lung disease and diabetes. Health workers, those with lower immunity due to disease or treatment, residents of nursing homes, children or teenagers on long-term aspirin therapy and people who have had their spleens removed, should also have the 'flu shot.
Dr O'Flanagan said: "The symptoms of influenza infection usually develop over a matter of a few hours and include a high temperature, sore muscles, dry cough, headache and sore throat.
"This is different from the common cold, which tends to come on more gradually and usually includes a runny nose and a normal temperature. Anyone in the high risk categories who develops influenza symptoms should contact their GP."
The weekly 'flu surveillance reports, along with further information on the virus and the vaccine, are available online at www.hpsc.ie.