H1N1 influenza 09 Infection

Last updated: 08 July 2009

Seasonal influenza and H1N1 influenza 09: what you need to know

H1N1 influenza 09 is a new influenza virus causing illness in people. This new virus will continue spreading within NSW, along with other influenza viruses seen each year. The H1N1 influenza 09 virus produces a mild illness in most people, a severe illness in some, and is a moderate illness overall. Because most people have no immunity to this virus, it is likely that more people will become sick with influenza ('the flu') this year, compared with previous years.

What are the symptoms of influenza?

Both H1N1 influenza 09 and normal seasonal influenza can produce symptoms of fever, chills, cough, sore throat, tiredness, and muscle aches, and sometimes vomiting and diarrhoea. Severe cases of influenza can result in breathing difficulty and pneumonia. Symptoms generally appear between two to four days after exposure. If you develop these symptoms you should stay home until your symptoms are gone.

Who is at an increased risk of severe illness from flu?

Some people are more likely to develop severe illness from both seasonal influenza and H1N1 influenza 09.This includes people who:

• Are pregnant (particularly during the second and third trimester)
• Have chronic lung disease (including asthma)
• Are very obese
• Have chronic heart conditions
• Have chronic kidney or liver disease
• Have blood disorders (including sickle cell disease)
• Have neurological disorders
• Have metabolic disorders (such as diabetes)
• Have weakened or suppressed immune systems (which may be caused by cancers, medications or HIV/AIDS)
• Are of Aboriginal of Torres Strait Islander background (of any age).

What should I do if I develop symptoms of the flu?

• If you are very sick, call triple zero (000) or go to an emergency department.
• If you have moderate illness, or are at higher risk of severe illness, you should visit your general practitioner as soon as you develop symptoms.
• If you are mildly unwell but not at increased risk, stay at home until you are better.
• When visiting a doctor, call ahead to see if you can be put in a separate waiting area. Ask for a mask if you are coughing and have to wait near other people.
• Cover your coughs and sneezes with a tissue. Put used tissues in the bin.
• Wash your hands with soap and running water for 10 seconds after coughing, sneezing or blowing your nose, and before touching other people or shared objects.

What should I do if I'm at increased risk of severe illness and someone else in my household has the

Wherever possible, keep away from the person who is sick, including sleeping in a separate room. Encourage the person who is sick to practice good cough and sneeze etiquette. Wash your hands often. If you are at very high risk (eg those with bone marrow suppression) speak with your treating specialist about whether prophylaxis with anti-influenza medication is appropriate.

Anti-influenza medications

Treatment with the anti-influenza medications oseltamivir (Tamiflu®) and zanamivir (Relenza®) may shorten the duration and severity of illness in people that already have influenza.

People at increased risk of severe illness should seek early treatment when they develop symptoms of influenza. Anti-influenza medications are supplied free to people at increased risk and to those with moderate or severe illness, if treatment can be started within 48 hours of symptom onset.

Other people may be able to obtain anti-influenza medications through a private prescription from your doctor. In most cases you should be able to continue taking your regular medications, but you should discuss with this your doctor. Pregnant or breastfeeding women can take anti-influenza medication if recommended by their doctor.

Caring for someone with influenza

• Offer medications containing paracetamol or ibuprofen to ease the symptoms. Always follow the directions.
• Do not give aspirin to children or teenagers without first speaking to your doctor.
• Keep the ill person as comfortable as possible. Rest is important.
• Offer healthy, nutritious food.
• Encourage the sick person to drink water.
• Keep disposable tissues and a rubbish bag within easy reach of the patient.
• Write down the date, time, and dose of medications taken by the patient so you know when the next dose can be taken.
• Wherever possible, maintain a distance of over one metre from the sick person, including sleeping separately.
• If you think the patient is getting worse, speak to your doctor for further advice. In an emergency call triple zero (000).

Know the warning signs of serious illness

If someone you are caring for experiences these signs and symptoms, seek urgent medical care.

Children:

• fast breathing or trouble breathing
• bluish skin colour
• not drinking enough fluids
• not waking up or not interacting
• being so irritable that the child does not want to be held
• flu-like symptoms improve but then return with fever and worsened cough
• fever with a rash.

Adults:

• difficulty breathing or shortness of breath
• pain or a feeling of pressure in the chest or abdomen
• sudden dizziness
• confusion
• severe or persistent vomiting.