ANALYSIS:Key aspect of influenza infection compared to the common cold or other respiratory viruses is the rapidity with which symptoms materialise, writes DR MUIRIS HOUSTONMedical Correspondent
NOW THAT the numbers of people infected with H1N1 flu have tripled in the space of a week, it is likely the rate of infection will continue to rise steadily. However, it is worth bearing in mind that even with the present rate of infection we are still below the peak influenza levels recorded last winter.
In terms of symptoms there is no difference between swine flu and regular flu. So if you have had a bout of flu (mild viral infections don’t count) in the past, you should recognise the symptoms immediately.
A key aspect of influenza infection compared to the common cold or other respiratory viruses is the rapidity with which symptoms materialise. Within several hours a victim can go from feeling well to developing extreme tiredness, muscle ache, cough and a temperature in excess of 38 degrees. They may not get all the symptoms – for example diarrhoea and vomiting have been reported in just 14 per cent of cases – but can expect to have two from the following list in addition to a high temperature: tiredness, headache, runny nose, sore throat, cough, shortness of breath, loss of appetite, muscle aches, diarrhoea and vomiting.
As we have entered the mitigation phase of our public health response, the diagnosis of H1N1 flu will be made on clinical grounds. In the majority of cases, formal laboratory tests will not be carried out, so your GP will make the diagnosis based on medical history and examination. You will be advised to rest and to take plenty of fluids. Paracetamol is recommended for both temperature reduction and the relief of various aches. You will not receive anti-viral medication (Tamiflu or Relenza) unless you have severe symptoms or are in a high-risk group such as being pregnant, severely obese or taking medication for asthma.
In the first instance you should not go to the GP surgery or hospital emergency department; instead make telephone contact with your local practice or out-of-hours service. If you are pregnant, have a sick child less than one year old, or your condition suddenly deteriorates, you should contact your doctor immediately. This advice also applies if your symptoms continue to get worse seven days after the onset of your illness or if you have a serious underlying illness such as chronic heart, lung or heart disease.
If you do require Tamiflu it must be taken within 48 hours of the onset of symptoms. The drug has been shown to reduce the duration of influenza as well as reducing the duration of symptoms. It also cuts the risk of developing secondary complications such as pneumonia. Potential side effects are generally mild and include nausea, vomiting and abdominal pain, which may be lessened by taking the tablets with food.
Dizziness and fatigue have been reported infrequently; there does not appear to be any major drug interaction between Tamiflu and other medications.
Antibiotics are of no use in the treatment of influenza. They may be prescribed if you develop a secondary bacterial infection.
It is estimated that each infected person infects between one and two others.
People are most infectious when symptoms are at their peak. As is the case with seasonal influenza a person with H1N1 flu is contagious from about one day before symptoms begin to seven days after they become ill. In order to reduce the risk of spreading influenza it is important to observe strict hand hygiene and to use disposable tissues, which should be destroyed after a single use.
- The HSE's advice for the public can be found at www.hse.ie